QMB3200 final study guide
Goodwill sells paperback books in their retail stores and wanted to examine the relationship between price and demand. The price of a particular novel was adjusted each week and the weekly sales were recorded in the table below. Sales Price 3 $12 4 $11 6 $10 10 $9 8 $8 10 $7 Complete a simple linear regression on these data to predict sales (y-variable), based on price (x-variable). What is the t-statistic for the slope of the regression line.
-4.4
If A and B are mutually exclusive events with P(A)=0.3 and P(B)=0.5, then P(A∩ B)= a. 0.15 b. 0.00 c. 0.20 d. 0.30
0.00
Please refer to the file called 'Social Networking Sites'. These data represent a sample of adults in different countries who use social networking sites. With these data, conduct a chi square goodness of fit test to determine whether the proportion of adults using social networking sites is equal for all four countries. Assume an alpha of .05. What is the resulting p-value?
0.000135
Ten percent of the items produced by a machine are defective. A random sample of 100 items is selected and checked for defects. What is the standard error of the proportion?
0.03
The Fortune 500 is comprised of Fortune magazine's annual list of the top 500 companies in the U.S. ranked by revenues (the Fortune 500 is a population of companies). According to Catalyst, 16% of the positions on corporate boards were held by women in a recent year. A random sample of 100 Fortune 500 companies was selected. What is the standard error of the proportion?
0.0328
Recently, 18.3% of the visitors to the travel site 'Travelocity' hailed from the Google search engine. A random sample of 130 visitors to the Travelocity site were selected. The standard error of the proportion is?
0.0339
Generation Y has been defined as those individuals who were born between 1981 and 1991. A 2010 survey by a credit counseling foundation found that 53% of the young adults in Generation Y pay their monthly bills on time) Suppose we take a random sample of 190 people from Generation Y. Calculate the standard error of the proportion.
0.0362
An experiment consists of four outcomes with P(E1)=0.2, P(E2)=0.3, and P(E3)=0.4. The probability of outcome E4 is a. 0.100 b. 0.500 c. 0.900 d. 0.024
0.100
Ten percent of the items produced by a machine are defective. A random sample of 100 items is selected and checked for defects. What is the probability that the sample will contain more than 13% defective units?
0.1587
The table below shows the number of cars sold last month by seven employees at Kraft Nissan and their number of years of sales experience. Experience Sales 1 8 2 6 2 7 4 14 5 9 6 13 8 10 Complete a simple linear regression using these data to predict sales (y-variable) based on experience (x-variable). What is the p-value for this regression?
0.198
A college has 230 full-time employees that are currently covered under the school's health care plan. The average out-of-pocket cost for the employees on the plan is $1,850 with a standard deviation of $520. The college is performing an audit of its health care plan and has randomly selected 30 employees to analyze their out-of-pocket costs. What is the probability that the sample mean will be between $1,865 and $1,915? Use decimal places without the % mark and round to two decimals.
0.2
If P(A)=0.62, P(B)=0.47 and P(A U B)=.88; then P(A ∩ B)= a. 0.6700 b. 0.2100 c. 1.9700 d. 0.2914
0.2100
In a random sample of 400 registered voters, 120 indicated they plan to vote for Candidate A. Determine a 95% confidence interval for the proportion of all the registered voters who will vote for Candidate A.
0.255 to 0.345
According to Responsys, the retailer Land's End sent an average of 376 e-mails to each of their customers over the last year. Assume that the standard deviation for the number of emails sent to each customer was 96. A random sample of 40 Land's End customers were selected. What is the probability that the average number of e-mails sent to each customer was between 360 and 374? Round to two decimal places as needed.
0.3
Six hundred consumers were asked whether they would like to purchase a domestic or a foreign automobile. Their responses are given below. Preference Frequency Domestic 240 Foreign 360 Develop a 95% confidence interval for the proportion of all consumers who prefer to purchase domestic automobiles.
0.3608 to 0.4392
If a penny is tossed four times and comes up heads all four times, the probability of heads on the fifth trial is a. zero b. 1/32 c. 0.5 d. larger than the probability of trials
0.5
If P(A)=0.85, P(A U B)=0.72, and P(A ∩ B)=0.66, then P(B)= a. 0.53 b. 0.15 c. 0.15 d. 0.28
0.53
A local credit union (mine) is tracking the loan decisions made by specific loan officers. The credit union is concerned that there may be loan officers that are not being consistent in the credit union's underwriting guidelines. As such, the credit union wants to determine whether or not the loan decisions are independent of the loan officer. Also, assume an alpha of .05. Conducting a chi square test of independence, what is the p-value?
0.531
Please refer to the file below called 'Bank Stats'. This file is a random sample of 30 SBA loans funded by different banks in the last few years. The bank called 'Random 200' is a fictitious bank developed as a control bank for the purpose of the study that was just completed. There are two tabs for this file, the first is the amount of the loan that was made, and the second is the interest rate charged on that loan. This file will be used for many applications, so don't close it and save your work. Also, be careful to read each question carefully. Assume that each question has an alpha of .05. Using the appropriate software, review the interest rates charged on loans for USNB, Wells Fargo, and Random 200 (the first three columns) to determine if they are equal. What is the p-value as a result of this test?
0.558
If P(A)=0.38, P(B)=0.83, and P(A∩ B)=0.57; then P( A U B)= a. 1.78 b. 0.78 c. 0.64 d. 1.21
0.64
An Epson inkjet printer ad advertises that the black ink cartridge will provide enough ink to print an average of 245 pages. Assume that this claim is accurate and that the standard deviation for this population is 15. A random sample of 33 customers were surveyed about the number of pages they were able to print with their black ink cartridges. What is the probability that the sample mean will be 246 pages or less?
0.649
If A and B are independent events with P(A)=0.2 and P(B)=0.6, then P(A U B)= a. 0.60 b. 0.68 c. 0.62 d. 0.12
0.68
The Wall Street Journal reported that a recently conducted travel survey found that 28% of baby boomers (those born between 1946 and 1964) took a cruise vacation in the last three years. A random sample of 75 baby boomers was selected. What is the probability that 23 or fewer of these individuals took a cruise in the last three years?
0.6965
The Beer Institute reported that the monthly consumption of beer is 1.7 gallons per person. A random sample of 36 adults was selected. Using a standard deviation of 0.5 gallons per month, what is the probability that the sample mean was between 1.6 and 1.8 gallons per month per person?
0.7698
Goodwill sells paperback books in their retail stores and wanted to examine the relationship between price and demand. The price of a particular novel was adjusted each week and the weekly sales were recorded in the table below. Sales Price 3....... $12 4...... $11 6....... $10 10...... $9 8...... $8 10...... $7 Complete a simple linear regression on these data to predict sales (y-variable), based on price (x-variable). What is the R-square.
0.829
Ten percent of the items produced by a machine are defective. A random sample of 100 items is selected and checked for defects. What is the probability that the sample will contain more than 2.5% defective parts? Round to 4 decimal places.
0.9938
A random sample of 34 golfers from a local golf course produces a sample score of 93.6. Assume that the population standard deviation is 4.2. The margin of error for a 95% confidence interval around the sample mean is?
1.41
Of five letters (A, B, C, D, and E), two letters are to be selected at random. How many possible selections are there? a. 20 b. 10 c. 5! d. 7
10
The table below shows the number of cars sold last month by seven employees at Kraft Nissan and their number of years of sales experience. Experience Sales 1 8 2 6 2 7 4 14 5 9 6 13 8 10 Complete a simple linear regression using these data to predict sales (y-variable) based on experience (x-variable). What is the expected number of cars sold for an employee with 5 years of experience?
10
Suppose that the average math SAT score for those attending FSU is 507.3 with a standard deviation of 68.2. A random sample of 43 students has been selected. The standard error of the mean for this sample is:
10.4
A coal company wants to determine a 95% confidence interval estimate for the average daily tonnage of coal that they mine. Assuming that the company reports that the standard deviation of daily output is 200 tons, how many days should they sample so that the margin of error will be 39.2 tons or less?
100
A simple random sample of 144 items resulted in a sample mean of 1080. The population standard deviation is known to be 240. Develop a 95% confidence interval for the population mean.
1040.8 to 1119.2
A random sample of 25 roundtrip flights between Orlando and San Jose, Costa Rica has an average price of $393.50 with a sample standard deviation of $50.30. What is the margin of error for 90% confidence interval around the sample mean?
17.21
A local credit union (mine) is tracking the loan decisions made by specific loan officers. The credit union is concerned that there may be loan officers that are not being consistent in the credit union's underwriting guidelines. As such, the credit union wants to determine whether or not the loan decisions are independent of the loan officer. Also, assume an alpha of .05. Conducting a chi square test of independence, what is the Chi Square test statistic?
2.21
The table below shows the number of cars sold last month by seven employees at Kraft Nissan and their number of years of sales experience. Experience Sales 1 8 2 6 2 7 4 14 5 9 6 13 8 10 Complete a simple linear regression using these data to predict sales (y-variable) based on experience (x-variable). What is the F-test statistic?
2.21
Please refer to the file below called 'Bank Stats'. This file is a random sample of 30 SBA loans funded by different banks in the last few years. The bank called 'Random 200' is a fictitious bank developed as a control bank for the purpose of the study that was just completed. There are two tabs for this file, the first is the amount of the loan that was made, and the second is the interest rate charged on that loan. This file will be used for many applications, so don't close it and save your work. Also, be careful to read each question carefully. Assume that each question has an alpha of .05. Use the appropriate software to determine if the mean loan amounts are equal among all 6 banks. What is the f-critical value?
2.27
The critical z-score for a 98% confidence level is?
2.33
Please refer to the file called 'Social Networking Sites'. These data represent a sample of adults in different countries who use social networking sites. With these data, conduct a chi square goodness of fit test to determine whether the proportion of adults using social networking sites is equal for all four countries. Assume an alpha of .05. What is the resulting Chi Square Test Statistics?
20.47
Please refer to the file below called 'Bank Stats'. This file is a random sample of 30 SBA loans funded by different banks in the last few years. The bank called 'Random 200' is a fictitious bank developed as a control bank for the purpose of the study that was just completed. There are two tabs for this file, the first is the amount of the loan that was made, and the second is the interest rate charged on that loan. This file will be used for many applications, so don't close it and save your work. Also, be careful to read each question carefully. Assume that each question has an alpha of .05. Using the appropriate software, review the interest rates charged on loans for all six banks to determine if they are equal. What is the mean square due to treatments as a result of this test?
203.54
The proprietor of a boutique in New York wanted to determine the average age of his customers. A random sample of 25 customers revealed an average age of 28 years with a standard deviation of 10 years. Determine a 95% confidence interval estimate for the average age of all his customers. Assume the population of customer ages is normally distributed.
23.872 to 32.128
A random sample of 30 students from QMB 3200 required an average of 43.4 minutes to complete their weekly quiz. Assume that the standard deviation to complete the quiz was 8.7 minutes. What is the margin of error for a 98% confidence interval around the sample mean?
3.9
A health club annually surveys its members. Last year, 33% of the members said they use the treadmill at least 4 times a week. How large of sample should be taken this year to estimate the percentage of members who use the treadmill at least 4 times a week? The estimate is desired to have a margin of error of 5% with a 95% level of confidence.
340
Computer Services, Inc. wants to determine a confidence interval for the average CPU time of their teleprocessing transactions. A sample of 196 transactions yielded a mean of 5 seconds. The population standard deviation is 1.4 seconds. Determine a 97% confidence interval for the average CPU time.
4.783 to 5.217
When sampling from a finite population, it is treated as an infinite population if n/N is less than or equal to _____ %.
5
The Highway Safety Department wants to study the driving habits of individuals. A sample of 41 cars traveling on the highway revealed an average speed of 60 miles per hour and a standard deviation of 7 miles per hour. The population of car speeds is approximately normally distributed. Determine a 90% confidence interval estimate for the speed of all cars.
58.16 to 61.84
Please refer to the file below called 'Bank Stats'. This file is a random sample of 30 SBA loans funded by different banks in the last few years. The bank called 'Random 200' is a fictitious bank developed as a control bank for the purpose of the study that was just completed. There are two tabs for this file, the first is the amount of the loan that was made, and the second is the interest rate charged on that loan. This file will be used for many applications, so don't close it and save your work. Also, be careful to read each question carefully. Assume that each question has an alpha of .05. Use the appropriate software to determine if the mean loan amounts are equal among all 6 banks. What is the F-test statistic?
7.14
Goodwill sells paperback books in their retail stores and wanted to examine the relationship between price and demand. The price of a particular novel was adjusted each week and the weekly sales were recorded in the table below. Sales Price 3 $12 4 $11 6 $10 10 $9 8 $8 10 $7 Complete a simple linear regression on these data to predict sales (y-variable), based on price (x-variable). How many books would Goodwill expect to sell based on a price of $8.75 per book?
8
A college has 230 full-time employees that are currently covered under the school's health care plan. The average out-of-pocket cost for the employees on the plan is $1,850 with a standard deviation of $520. The college is performing an audit of its health care plan and has randomly selected 30 employees to analyze their out-of-pocket costs. Calculate the standard error of the mean.
88.72
A method of assigning probabilities that assumes the experimental outcomes are equally likely is referred to as the a. subjective method b. classical method c. objective method d. experimental method
Classical method
When the assumption of equally likely outcomes is used to assign probability values, the method used to assign probabilities is referred to as the a. relative frequency method b. probability method c. classical method d. subjective method
Classical method
NOT ON TEST: A lottery is conducted using three urns. Each urn contains chips numbered from 0 to 9. One chip is selected at random from each urn. The total number of sample points in the sample space a. 100 b. 30 c. 729 d. 1,000
D. 1,000 (NOT ON TEST DONT WORRY)
Apple is considering offering the new version of the iPad in color options other than black and white. Before deciding, Apple would like to survey potential iPad users on their preferences. Management feels that the gender of the person will affect their response. As a result, Apple would like to ensure that the sample is composed of an equal number of male and female respondents. This is an example of 'cluster sampling'. True or False
False
Given that a 95% confidence interval is (6.5, 12.5), we can state that there is a 95% probability that the true population mean is between 6.5 and 12.5. True or False
False
Please refer to the file below called 'Bank Stats'. This file is a random sample of 30 SBA loans funded by different banks in the last few years. The bank called 'Random 200' is a fictitious bank developed as a control bank for the purpose of the study that was just completed. There are two tabs for this file, the first is the amount of the loan that was made, and the second is the interest rate charged on that loan. This file will be used for many applications, so don't close it and save your work. Also, be careful to read each question carefully. Assume that each question has an alpha of .05. Using the appropriate software, review the interest rates charged on loans for all six banks to determine if they are equal. From your analysis, you can conclude that all banks are charging interest rates that are essentially the same. True or False
False
The attached Excel file 'SBA Loans, Chapter 3 Quiz', is a list of 200 actual loans made with the assistance of the Small Business Administration (SBA). Open this file and use this file to answer specific questions about these data. Do not close the file as you will need it for several questions. Referring to the interest rates, because the skewness is positive, the mean interest rate will be below the median interest rate. True or False
False
The higher the standard error of the mean, the less variation you will notice from one sample mean to the next as they are drawn from the population. True or False
False
The sampling distribution of the mean describes the pattern that individual observations tend to follow when randomly drawn from a population. True or False
False
When the slope of a population regression line equals zero, we conclude that there is a linear relationship between the dependent and independent variables. True or False
False
If A and B are independent events with P(A)=.1 and P(B)=.4, then a. P(A∩B)=0 b. P(A U B )=.5 c. P(A ∩ B)=.04 d. P(A ∩ B)=.25
P(A ∩ B)=.04
Which of the following statements is (are) always true? a. P(A)+P(B)=1 b. P(A)=1-P(A^c) c. -1 ≤ P(Ei) ≤ 1 d. both P(A)=1-P(A^c) and P(A)+P(B)=1
P(A)=1-P(A^c)
The national average for a price of regular gasoline was recently reported to be $3.29 per gallon. The standard deviation for the price of regular gasoline is $0.12 per gallon. A random sample of 33 gas stations had an average price of $3.26 per gallon. Which of the following statements is correct? a. The interval that contains 95% of the sample means is $3.17 and $3.41. Because the sample mean is between these two values, we have support that the average price for regular gasoline is $3.29 per gallon. b. The interval that contains 95% of the sample means is $3.20 and $3.38. Because the sample mean is between these two values, we have support that the average price for regular gasoline is $3.29 per gallon. c. The interval that contains 95% of the sample means is $3.23 and $3.35. Because the sample mean is between these two values, we have support that the average price for regular gasoline is $3.29 per gallon. d. The interval that contains 95% of the sample means is $3.25 and $3.33. Because the sample mean is between these two values, we have support that the average price for regular gasoline is $3.29 per gallon.
The interval that contains 95% of the sample means is $3.25 and $3.33. Because the sample mean is between these two values, we have support that the average price for regular gasoline is $3.29 per gallon.
Please refer to the file below called 'Bank Stats'. This file is a random sample of 30 SBA loans funded by different banks in the last few years. The bank called 'Random 200' is a fictitious bank developed as a control bank for the purpose of the study that was just completed. There are two tabs for this file, the first is the amount of the loan that was made, and the second is the interest rate charged on that loan. This file will be used for many applications, so don't close it and save your work. Also, be careful to read each question carefully. Assume that each question has an alpha of .05. Use the appropriate software to determine if the mean loan amounts are equal among all 6 banks. Given the results of the appropriate statistical tests, the null hypothesis should be rejected. True or False
True
The definition of a 90% confidence interval is that we expect that close to 90% of a large number of sample means drawn from a population will produce confidence intervals that include that population's mean. True or False
True
When the p-value for testing the significance of the regression slope is less than alpha, we conclude that there is a significant relationship between the dependent and independent variables. True or False
True
The attached Excel file 'SBA Loans, Chapter 3 Quiz', is a list of 200 actual loans made with the assistance of the Small Business Administration (SBA). Open this file and use this file to answer specific questions about these data. Do not close the file as you will need it for several questions. What is the interquartile range for the loan amounts? a. $175,000 b. $3,757,500 c. $200,000 d. None of the above
a. $175,000
The probability distribution for the daily sales at Michael's Co. is given below. Daily Sales ($1,000s) Probability 40 0.1 50 0.4 60 0.3 70 0.2 The expected daily sales are a. $56,000 b. $70,000 c. $50,000 d. $55,000
a. $56,000
A random sample of 25 roundtrip flights between Orlando and San Jose, Costa Rica has an average price of $393.50 with a sample standard deviation of $50.30. What is the 95% confidence interval around the sample mean? a. (372.74, 414.26) b. (383.44, 403.56) c. (353.26, 433.74) d. (388.47, 398.53)
a. (372.74, 414.26)
Count of Hwy MPG Column Labels Row Labels 15-19 20-24 25-29 30-34 35-39 40-44 Grand Total Compact 3 56 Large 2 24 Midsize 3 69 Grand Total 8 18 54 45 16 8 149 How many large cars get between 40 to 44 miles per gallon? a. 0 b. 2 c. 4 d. 5
a. 0
Using the attached file, 'Ports', which is an excel file that records the annual tonnage of cargo handled at the top 25 ports, develop a frequency distribution with class widths of 25, starting with 25. What is the relative percent frequency distribution for tonnage between 100-124.9? a. 0% b. 8% c. 12% d. none of the above
a. 0%
Z is a standard normal random variable. The P(z ≥ 2.11) equals a. 0.0174 b. 0.9821 c. 0.4821 d. 0.5
a. 0.0174
The number of electrical outages in a city varies from day to day. Assume that the number of electrical outages (x) in the city has the following probability distribution. x..... f(x) 0..... 0.80 1..... 0.15 2..... 0.04 3..... 0.01 The mean and the standard deviation for the number of electrical outages (respectively) are a. 0.26 and 0.577 b. 3 and 0.01 c. 0 and 0.8 d. 2.6 and 5.77
a. 0.26 and 0.577
The random variable x is known to be uniformly distributed between 70 and 90. The probability of x having a value between 80 to 95 is a. 0.5 b. 0.75 c. 0.05 d. 1
a. 0.5
Consider the continuous random variable x, which has a uniform distribution over the interval from 20 to 28. The probability that x will take on a value between 21 and 25 is a. 0.500 b. 1.000 c. 0.250 d. 0.125
a. 0.500
The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes. The probability that her trip will take longer than 60 minutes is a. 0.600 b. 0.02 c. 0.40 d. 1.00
a. 0.600
The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds. The probability of a player weighing less than 250 pounds is a. 0.9772 b. 0.5000 c. 0.0528 d. 0.4772
a. 0.9772
Z is a standard normal random variable. What is the value of z if the area between -z and z is 0.754? a. 1.16 b. 0.377 c. 2.16 d. 0.123
a. 1.16
Given that z is a standard normal random variable, what is the value of z if the area to the right of z is 0.1112? a. 1.22 b. 0.3888 c. 2.22 d. 3.22
a. 1.22
Given that z is a standard normal random variable, what is the value of z if the area to the left of z is 0.9382? a. 1.54 b. 2.1 c. 1.77 d. 1.8
a. 1.54
The sum of the percent frequencies for all classes will always equal a. 100 b. the number of items in the study c. the number of classes d. one
a. 100
SSTR=6,750 H0:μ1=μ2=μ3=μ4 SSE=8,000 Ha: at least one mean is different nT = 20 The mean square between treatments (MSTR) equals a. 2,250 b. 1,687.5 c. 400 d. 500
a. 2,250
In order to determine whether or not a particular medication was effective in curing the common cold, one group of patients was given the medication, while another group received sugar pills. The results of the study are shown below. The hypothesis is to be tested at the 5% level of significance. The critical value from the table equals a. 3.84 b. 5.99 c. 7.81 d. 9.34
a. 3.84
In a completely randomized experimental design involving five treatments, thirteen observations were recorded for each of the five treatments. The following information is provided. SSTR = 200 (Sum Square Between Treatments) SST = 800 (Total Sum Square) The mean square between treatments (MSTR) is a. 50.00 b. 10.00 c. 12.00 d. 3.34
a. 50.00
A researcher has collected the following sample data. 5 12 6 8 5 6 7 5 12 4 The median is a. 6 b. 5 c. 8 d. 7
a. 6
Suppose a sample of 150 individuals was taken. Their gender and their preferred computer manufacturer was noted. Partial results of the study follow in a cross tabulation of column percentages. If 80 of those in the study prefer Apple computers, how many males preferred Apple computers? a. 64 b. 30 c. 120 d. 80
a. 64
A name closely associated with the binomial probability distribution is a. Bernoulli b. de Moivre c. Pareto d. Poisson
a. Bernoulli
The F ratio in a completely randomized ANOVA is the ratio of a. MSTR/MSE b. MST/MSE c. MSE/MST d. MSE/MSTR
a. MSTR/MSE
Excel's __________ function can be used to compute the expected value of a discrete random variable. a. SUMPRODUCT b. VAR c. MEDIAN d. AVERAGE
a. SUMPRODUCT
Refer to the attached file 'LivingArea', where do most people live now? a. city b. rural c. small town d. suburbs
a. city
An experiment consists of making 80 telephone calls in order to sell a particular insurance policy. The random variable in this experiment is the number of sales made. This random variable is a a. discrete random variable b. continuous random variable c. complex random variable d. None of the answers is correct.
a. discrete random variable
Beverage Teens Adults Total Coffee 50 200 250 Tea 100 150 250 Soft Drink200 200 400 Other 50 50 100 400 600 1,000 Assume an alpha of .05, the result of the test is that the a. hypothesis of independence can be rejected b. hypothesis of independence cannot be rejected c. test is inconclusive d. None of these alternatives is correct.
a. hypothesis of independence can be rejected
A least squares regression line a. may be used to predict a value of y if the corresponding x value is given b. implies a cause-effect relationship between x and y c. can only be determined if a good linear relationship exists between x and y d. All of these answers are correct.
a. may be used to predict a value of y if the corresponding x value is given
The 50th percentile is the a. median b. mean c. third quartile d. mode
a. median
If the coefficient of correlation is a negative value, then the coefficient of determination a. must be positive b. must be zero c. can be either negative or positive d. must also be negative
a. must be positive
In computing the standard error of the mean, the finite population correction factor is not used when a. n/N ≤ 0.05 b. N/n ≤ 0.05 c. n/N > 0.05 d. n ≥ 30
a. n/N ≤ 0.05
A numerical description of the outcome of an experiment is called a a. random variable b. variance c. descriptive statistic d. probability function
a. random variable
In the analysis of variance procedure (ANOVA), factor refers to a. the independent variable b. different levels of a treatment c. the critical value of F d. the dependent variable
a. the independent variable
The interquartile range is used as a measure of variability to overcome what difficulty of the range? a. the range is influenced too much by extreme values b. the range is negative c. the sum of the range variances is zero d. the range is difficult to compute
a. the range is influenced too much by extreme values
The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes. The probability that her trip will take exactly 50 minutes is a. zero b. 0.02 c. 0.06 d. 0.20
a. zero
The expected value of the random variable x-bar is a. μ b. the sample size c. σ d. the standard error
a. μ
The attached Excel file 'SBA Loans, Chapter 3 Quiz', is a list of 200 actual loans made with the assistance of the Small Business Administration (SBA). Open this file and use this file to answer specific questions about these data. Do not close the file as you will need it for several questions. What is the average loan size? a. $237,439.25 b. $229,556.50 c. $200,000.00 d. None of the above
b. $229,556.50
Forty percent of all registered voters in a national election are female. A random sample of 5 voters is selected. The probability that there are no females in the sample is a. 0.7780 b. 0.0778 c. 0.3456 d. 0.5000
b. 0.0778
Z is a standard normal random variable. The P(1.05 ≤ z ≤ 2.13) equals a. 0.8365 b. 0.1303 c. 0.4834 d. None of the alternative answers is correct.
b. 0.1303
Consider the continuous random variable x, which has a uniform distribution over the interval from 20 to 28. The probability that x will take on a value of at least 26 is a. 0.125 b. 0.250 c. 1.000 d. 0.000
b. 0.250
Forty percent of all registered voters in a national election are female. A random sample of 5 voters is selected. The probability that the sample contains 2 female voters is a. 0.5000 b. 0.3456 c. 0.0778 d. 0.7780
b. 0.3456
In a regression analysis if SSE = 500 and SSR = 300, then the coefficient of determination is a. 0.1666 b. 0.3750 c. 1.6666 d. 0.6000
b. 0.3750
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. What is the probability that a randomly selected item will weigh between 11 and 12 ounces? a. 0.4332 b. 0.4772 c. 0.9104 d. 0.0440
b. 0.4772
The assembly time for a product is uniformly distributed between 6 to 10 minutes. The probability of assembling the product between 7 to 9 minutes is a. zero b. 0.50 c. 1 d. 0.20
b. 0.50
The following represents the probability distribution for the daily demand of microcomputers at a local store. Demand Probability 0 0.1 1 0.2 2 0.3 3 0.2 4 0.2 The probability of having a demand for at least two microcomputers is a. 1.0 b. 0.7 c. 0.4 d. 0.3
b. 0.7
The numbers of miles from their residence to their place of work for 120 employees is shown below. The relative frequency of employees who drive 10 miles or less to work is: a. 0.85 b. 0.71 c. 0.25 d. 85
b. 0.71
X is a normally distributed random variable with a mean of 8 and a standard deviation of 4. The probability that x is between 1.48 and 15.56 is a. 0.0222 b. 0.9190 c. 0.5222 d. 0.4190
b. 0.9190
The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours Frequency 0 − 9 20 10 − 19 80 20 − 29 200 30 − 39 100 The percentage of students working 10 − 19 hours is a. 25% b. 20% c. 80% d. 75%
b. 20%
Count of Hwy MPG Column Labels Row Labels 15-19 20-24 25-29 30-34 35-39 40-44 Grand Total Compact 3 56 Large 2 24 Midsize 3 69 Grand Total 8 18 54 45 16 8 149 How many compact cars get between 30 to 34 miles per gallon? a. 20 b. 22 c. 17 d. 12
b. 22
The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours Frequency 0 − 9 20 10 − 19 80 20 − 29 200 30 − 39 100 The percentage of students working 19 hours or less is a. 75% b. 25% c. 20% d. 80%
b. 25%
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. What percentage of items will weigh at least 11.7 ounces? a. 53.22% b. 3.22% c. 46.78% d. 96.78%
b. 3.22%
The following is part of an ANOVA table, which was the results of three treatments and a total of 15 observations. The mean square between treatments (MSTR) is a. 36 b. 32 c. 16 d. 8
b. 32
The use of the normal probability distribution as an approximation of the sampling distribution of is based on the condition that both np and n(1 - p) equal or exceed a. 30 b. 5 c. 10 d. .05
b. 5
Refer to the excel file 'HotelRating', which is a survey taken by TripAdvisor to determine people's perception a specific hotel brand. Based on these data, what percentage of people consider this hotel brand to be 'terrible?' a. 41 b. 6.3% c. 32.4% d. none of the above
b. 6.3%
In a completely randomized experimental design involving five treatments, thirteen observations were recorded for each of the five treatments. The following information is provided. SSTR = 200 (Sum Square Between Treatments) SST = 800 (Total Sum Square) The number of degrees of freedom corresponding to within treatments is a. 5 b. 60 c. 4 d. 59
b. 60
The attached Excel file 'SBA Loans, Chapter 3 Quiz', is a list of 200 actual loans made with the assistance of the Small Business Administration (SBA). Open this file and use this file to answer specific questions about these data. Do not close the file as you will need it for several questions. What is the standard deviation of the loan terms (TerminMonths)? a. 4.83 b. 68.4 c. 68.2 d. None of the above
b. 68.4
Using the attached file, 'Ports', which is an excel file that records the annual tonnage of cargo handled at the top 25 ports, develop a frequency distribution with class widths of 25, starting with 25. What is the cumulative percent frequency distribution for tonnage between 25-74.9? a. 36% b. 80% c. 44% d. none of the above
b. 80%
Using the attached file, 'Ports', which is an excel file that records the annual tonnage of cargo handled at the top 25 ports, develop a frequency distribution with class widths of 25, starting with 25. What is the frequency distribution for tonnage between 50-74.9? a. 7 b. 9 c. 8% d. 12
b. 9
The attached Excel file 'SBA Loans, Chapter 3 Quiz', is a list of 200 actual loans made with the assistance of the Small Business Administration (SBA). Open this file and use this file to answer specific questions about these data. Do not close the file as you will need it for several questions. What is the 75th percentile for interest rates charged on these loans? a. 75% b. 9.25% c. 4.45% d. None of the above
b. 9.25%
Excel's __________ can be used to construct a frequency distribution for categorical data. a. FREQUENCY function b. COUNTIF function c. SUM function d. DISTRIBUTION function
b. COUNTIF function
The ________ is used to test the significance of the population coefficient of determination. a. Student t-distribution b. F-distribution c. Chi-square distribution d. Normal distribution
b. F-distribution
According to the Gallup Crime Survey, 26% of gun owners are women. From a random sample of 160 gun owners, 26 were female. Which of the following statements is correct? a. The interval that contains 95% of the sample proportions is 0.192 and 0.328. Because the sample proportion is between these two values, we have support that the proportion of gun owners who are female is 26% b. The interval that contains 95% of the sample proportions is 0.192 and 0.328. Because the sample proportion is not between these two values, we do not have support that the proportion of gun owners who are female is 26% c. The interval that contains 95% of the sample proportions is 0.225 and 0.295. Because the sample proportion is between these two values, we have support that the proportion of gun owners who are female is 26% d. The interval that contains 95% of the sample proportions is 0.225 and 0.295. Because the sample proportion is not between these two values, we do not have support that the proportion of gun owners who are female is 26%
b. The interval that contains 95% of the sample proportions is 0.192 and 0.328. Because the sample proportion is not between these two values, we do not have support that the proportion of gun owners who are female is 26%
The variance for the binomial probability distribution is a. Var(x) = np b. Var(x) = np(1 − p) c. Var(x) = n(1 − p) d. Var(x) = p(1 − p)
b. Var(x) = np(1 − p)
The binomial probability distribution is used with a. a continuous random variable b. a discrete random variable c. any distribution, as long as it is not normal d. All of these answers are correct.
b. a discrete random variable
Each individual outcome of an experiment is called a. the sample space b. a sample point c. an experiment d. an individual
b. a sample point
Experimental outcomes that are based on measurement scales such as time, weight, and distance can be described by _____ random variables. a. discrete b. continuous c. uniform d. intermittent
b. continuous
A measure of the strength of the relationship between two variables is the a. standard error of the estimate b. correlation coefficient c. coefficient of determination d. slope b1 of the estimated regression line
b. correlation coefficient
Whenever using the t distribution in interval estimation, we must assume that the a. population is approximately normal b. degrees of freedom equals n − 1 c. finite population correction factor is necessary d. sample size is less than 30
b. degrees of freedom equals n − 1
For a sample size of two or more, the standard error of the mean must be: a. equal to the population standard deviation b. less than the population standard deviation c. less than the population mean d. more than the population mean
b. less than the population standard deviation
A data point (observation) that does not fit the trend shown by the remaining data is called a(n) a. residual b. outlier c. point estimate d. None of the other answers is correct.
b. outlier
The highest point of a normal curve occurs at a. approximately three standard deviations to the right of the mean b. the mean c. one standard deviation to the right of the mean d. two standard deviations to the right of the mean
b. the mean
Which of the following is not a property of a binomial experiment? a. each outcome can be referred to as a success or a failure b. the probabilities of the two outcomes can change from one trial to the next c. the experiment consists of a sequence of n identical trials d. the trials are independent
b. the probabilities of the two outcomes can change from one trial to the next
The t distribution should be used whenever a. the sample size is less than 30 b. the sample standard deviation is used to estimate the population standard deviation c. the population is not normally distributed d. None of the other answers are correct.
b. the sample standard deviation is used to estimate the population standard deviation
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. What is the random variable in this experiment? a. the normal distribution b. the weight of items produced by a machine c. 2 ounces d. 8 ounces
b. the weight of items produced
In regression analysis, the F test will provide the same conclusion as the t test if a. there is a positive correlation between x and y b. there is only one independent variable c. there is only one dependent variable d. the y-intercept is positive
b. there is only one independent variable
The 75th percentile is also the a. second quartile b. third quartile c. fourth quartile d. first quartile
b. third quartile
The number of sick days taken (per month) by 200 factory workers is summarized below. Number of Days Frequency 0 − 5 120 6 − 10 65 11 − 15 14 16 − 20 1 The relative frequency of workers who took 10 or fewer sick days a. was 185 b. was 0.925 c. was 93 d. was 15
b. was 0.925
The attached Excel file 'SBA Loans, Chapter 3 Quiz', is a list of 200 actual loans made with the assistance of the Small Business Administration (SBA). Open this file and use this file to answer specific questions about these data. Do not close the file as you will need it for several questions. What is the trimmed mean for loan amounts at the 10% level? a. $175,000 b. $64,245 c. $142,168 d. None of the above
c. $142,168
In the future, I am anticipating a home improvement project and my contractor has provided me an estimate of the number of hours that specific tradesmen would work on my house, and the rate for that tradesman. Based on the information attached, what is the weighted cost per hour for this project? This is the only question you will have with this file. a. $2,800 b. $20.50 c. $18.67 d. None of the above
c. $18.67
The student body of a large university consists of 60% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample exactly two are female? a. 0.0896 b. 0.0007 c. 0.0413 d. 0.2936
c. 0.0413
The student body of a large university consists of 60% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample at least 7 are female? a. 0.0896 b. 0.0168 c. 0.1064 d. 0.8936
c. 0.1064
In a regression analysis if SST = 4500 and SSE = 1575, then the coefficient of determination is a. 2.85 b. 0.45 c. 0.65 d. 0.35
c. 0.65
The following is part of an ANOVA table, which was the results of three treatments and a total of 15 observations. The number of degrees of freedom corresponding to within treatments is a. 2 b. 3 c. 12 d. 15
c. 12
Part of an ANOVA table is shown below. The number of degrees of freedom corresponding to within treatments is a. 22 b. 4 c. 18 d. 5
c. 18
The following is part of an ANOVA table, which was the results of three treatments and a total of 15 observations. The number of degrees of freedom corresponding to between treatments is a. 4 b. 3 c. 2 d. 12
c. 2
The z value for a 97.8% confidence interval estimation is a. 1.96 b. 2.02 c. 2.29 d. 2.00
c. 2.29
SSTR=6,750 H0:μ1=μ2=μ3=μ4 SSE=8,000 Ha: at least one mean is different nT = 20 he null hypothesis is to be tested at the 5% level of significance. The critical value from the table is a. 2.87 b. 8.7 c. 3.24 d. 4.08
c. 3.24
The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours Frequency 0 − 9 20 10 − 19 80 20 − 29 200 30 − 39 100 The midpoint of the last class is a. 34 b. 35 c. 34.5 d. 50
c. 34.5
The attached Excel file 'SBA Loans, Chapter 3 Quiz', is a list of 200 actual loans made with the assistance of the Small Business Administration (SBA). Open this file and use this file to answer specific questions about these data. Do not close the file as you will need it for several questions. What is the skewness of the loan amounts in this sample a. skewed to the left b. Highly skewed to the left c. 4.19 d. 4.04
c. 4.19
Referring to the file, 'T-Bond returns', what is the geometric mean return for the time period presented? This is the only question for this file. a. 5.03% b. 4.92% c. 4.58% d. None of the above
c. 4.58%
Information on the number of new teachers hired in a school district for each of 4 years is given in the table below. The percent frequency of new hires in 1998 is: a. 0.40% b. 20% c. 40% d. 80%
c. 40%
The median of a sample will always equal the a. mode b. mean c. 50th percentile d. all of these answers are correct
c. 50th percentile
The attached Excel file 'SBA Loans, Chapter 3 Quiz', is a list of 200 actual loans made with the assistance of the Small Business Administration (SBA). Open this file and use this file to answer specific questions about these data. Do not close the file as you will need it for several questions. What is the average interest rate on these loans? a. 6.00% b. 6.50% c. 7.31% d. None of the above
c. 7.31%
The assembly time for a product is uniformly distributed between 6 to 10 minutes. The expected assembly time (in minutes) is a. 16 b. 2 c. 8 d. 4
c. 8
Refer to the excel file 'HotelRating', which is a survey taken by TripAdvisor to determine people's perception a specific hotel brand. Based on these data, what percentage of people consider this hotel brand to be rated average or higher? a. 16.5% b. 45.3% c. 84.1% d. none of the above
c. 84.1%
If P(A ∩ B) = 0, a. either P(A) = 0 or P(B) = 0 b. A and B are independent events c. A and B are mutually exclusive events d. P(A) + P(B) = 1
c. A and B are mutually exclusive events
A survey by American Express spending reported that the average amount spent on a wedding gift for a family member was $166. A random sample of 45 people who purchased wedding gifts spent an average of $160.50. Assume that the population standard deviation is $38.00. Use a 95% confidence to test the validity of this claim and choose the best answer below. a. Because this confidence interval does not include $166, the report by American Express Spending is not validated. b. Because this confidence interval does not include $166, the report by American Express Spending is validated. c. Because this confidence interval does include $166, the report by American Express Spending is validated. d. Because this confidence interval does include $166, the report by American Express Spending is not validated.
c. Because this confidence interval does include $166, the report by American Express Spending is validated.
Excel's ____ function is used to perform a test of independence. a. z-Test: Two Sample for Means b. t-Test: Two Sample Assuming Equal Variances c. CHISQ.TEST d. NORM.S.DIST
c. CHISQ.TEST
Excel's __________ function can be used to compute the sample covariance. a. VAR b. MAX c. COVARIANCE.S d. CORREL
c. COVARIANCE.S
Excel's __________ can be used to construct a cross-tabulation. a. Chart Tools b. SUM function c. PivotTable Report d. COUNTIF function
c. PivotTable Report
In statistical experiments, each time the experiment is repeated a. the same outcome must occur b. the same outcome can not occur again c. a different outcome may occur d. None of the other answers is correct.
c. a different outcome may occur
In the set of all past due accounts, let the event A mean the account is between 31 and 60 days past due and the event B mean the account is that of a new customer. The intersection of A and B is a. all new customers b. all accounts fewer than 31 or more than 60 days past due c. all new customers whose accounts are between 31 and 60 days past due d. all accounts from new customers and all accounts that are from 31 to 60 days past due
c. all new customers whose accounts are between 31 and 60 days past due
A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the a. approximation theorem b. normal probability theorem c. central limit theorem d. central normality theorem
c. central limit theorem
A random variable that can assume only a finite number of values is referred to as a(n) a. discrete probability function b. infinite sequence c. discrete random variable d. finite sequence
c. discrete random variable
A random variable that can assume only a finite number of values is referred to as a(n) a. infinite sequence b. discrete probability function c. discrete random variable d. finite sequence
c. discrete random variable
A measure of the average value of a random variable is called a(n) a. variance b. standard deviation c. expected value d. None of the answers is correct.
c. expected value
The expected value of a discrete random variable a. is the most likely or highest probability value for the random variable b.will always be one of the values x can take on, although it may not be the highest probability value for the random variable c. is the average value for the random variable over many repeats of the experiment d. All of the answers are correct.
c. is the average value for the random variable over many repeats of the experiment
If a data set has an even number of observations, the median a. can not be determined b. is the average value of the two middle items c. is the average value of the two middle items when all items are arranged in ascending order d. must be equal to the mean
c. is the average value of the two middle items when all items are arranged in ascending order
Events that have no sample points in common are a. posterior events b. complements c. mutually exclusive events d. independent events
c. mutually exclusive events
The empirical rule states that, for data having a bell-shaped distribution, the percentage of data values being within three standard deviations of the mean is a. approximately 95 b. approximately 85 c. nearly 100 d. approximately 90
c. nearly 100
For data skewed to the left, the skewness is a. less than 1 b. positive c. negative d. between 0 and .5
c. negative
The binomial probability distribution is most symmetric when a. n equals p b. n is 30 or greater c. p equals 0.5 d. p approaches 1
c. p equals 0.5
Increasing the sample size when calculating a confidence interval while keeping the confidence level constant will: a. reduce the margin of error resulting in a less precise confidence interval b. increase the margin of error resulting in a narrower confidence interval c. reduce the margin of error resulting in a more precise confidence interval d. increase the margin of error resulting in a wider confidence interval
c. reduce the margin of error resulting in a more precise confidence interval
When the results of experimentation or historical data are used to assign probability values, the method used to assign probabilities is referred to as the a. posterior method b. subjective method c. relative frequency method d. classical method
c. relative frequency method
The technique of ________ enables us to describe a straight line that best fits a series of ordered pairs (x,y ). a. Analysis of variance b. correlation analysis c. simple regression analysis d. hypothesis testing
c. simple regression analysis
An important numerical measure of the shape of a distribution is the a. variance b. relative location c. skewness d. correlation coefficient
c. skewness
Refer to the attached file 'LivingArea', where would most people want to live? a. city b. rural c. small town d. suburbs
c. small towns
The symbol σ is used to represent the a. variance of the population b. standard deviation of the sample c. standard deviation of the population d. None of the other answers are correct.
c. standard deviation of the population
A weighted average of the value of a random variable, where the probability function provides weights is known as a. a probability function b. a random variable c. the expected value d. None of the answers is correct
c. the expected value
The ANOVA procedure is a statistical approach for determining whether or not a. the means of more than two samples are equal b. the means of two or more samples are equal c. the means of two or more populations are equal d. the means of two samples are equal
c. the means of two or more populations are equal
Which of the following is a characteristic of a binomial experiment? a. at least 2 outcomes are possible b. the probability of success changes from trial to trial c. the trials are independent d. All of these answers are correct.
c. the trials are independent
The number of sick days taken (per month) by 200 factory workers is summarized below. Number of Days Frequency 0 − 5 120 6 − 10 65 11 − 15 14 16 − 20 1 The number of workers who took less than 11 sick days per month a. was 65 b. was 15 c. was 185 d. was 200
c. was 185
The assembly time for a product is uniformly distributed between 6 to 10 minutes. The probability of assembling the product in less than 6 minutes is a. 0.15 b. 1 c. zero d. 0.50
c. zero
A random sample of 34 golfers from a local golf course produces a sample score of 93.6. Assume that the population standard deviation is 4.2. The 90% confidence interval around the sample mean is? a. (89.0, 98.3) b. (90.5, 96.7) c. (93.2, 94.0) d. (92.4, 94.8)
d. (92.4, 94.8)
Z is a standard normal random variable. What is the value of z if the area to the right of z is 0.9803? a. 3.06 b. 0.0997 c. 0.4803 d. -2.06
d. -2.06
Refer to the Excel file 'Housing'. What is the correlation coefficient between the jobless rate and the loan delinquency rate? This is the only question you will have using this file. a. .34 b. 1.24 c. 1.44 d. .44
d. .44
For a standard normal distribution, the probability of z ≤ 0 is a. one b. zero c. -0.5 d. 0.5
d. 0.5
In a regression analysis if SSE = 200 and SSR = 300, then the coefficient of determination is a. 0.4000 b. 0.6667 c. 1.5000 d. 0.6000
d. 0.6000
The assembly time for a product is uniformly distributed between 6 to 10 minutes. The probability of assembling the product in 7 minutes or more is a. 1 b. zero c. 0.25 d. 0.75
d. 0.75
Assume that you have a binomial experiment with p = 0.4 and a sample size of 50. The variance of this distribution is a. 3.46 b. Not enough information is given to answer this question. c. 20 d. 12
d. 12
The t value with a 95% confidence and 24 degrees of freedom is a. 2.069 b. 2.492 c. 1.711 d. 2.064
d. 2.064
A survey of 400 college seniors resulted in the following cross-tabulation regarding their undergraduate major and whether or not they plan to go to graduate school. What percentage of the undergraduates surveyed are majoring in Engineering? a. 151% b. 42% c. 400% d. 38%
d. 38%
Exhibit 3-1 A researcher has collected the following sample data. 5 12 6 8 5 6 7 5 12 4 The mode is a. 8 b. 7 c. 6 d. 5
d. 5
The table below gives beverage preferences for random samples of teens and adults. Beverage Teens Adults Total Coffee 50 200 250 Tea 100 150 250 Soft Drink200 200 400 Other 50 50 100 400 600 1,000 The calculated value for this test for independence is a. 82.5 b. 8.4 c. 0 d. 62.5
d. 62.5
Excel's Chart Tools can be used to construct a a. bar chart b. pie chart c. histogram d. All of these can be constructed using Excel's Chart Tools.
d. All of these can be constructed using Excel's Chart Tools.
A local bottling company has determined the number of machine breakdowns per month and their respective probabilities as shown below. #Breakdowns Probability 0 0.12 1 0.38 2 0.25 3 0.18 4 0.07 The probability of at least 3 breakdowns in a month is a. 0.5 b. 0.10 c. 0.30 d. None of the alternative answers is correct.
d. None of the alternative answers is correct.
A local bottling company has determined the number of machine breakdowns per month and their respective probabilities as shown below. #Breakdowns Probability 0................... 0.12 1................... 0.38 2................... 0.25 3 ...................0.18 4................... 0.07 The probability of no breakdowns in a month is a. 0.88 b. 0.00 c. 0.50 d. None of the alternative answers is correct.
d. None of the alternative answers is correct.
Z is a standard normal random variable. The P(1.41 < z < 2.85) equals a. 0.4772 b. 0.3413 c. 0.8285 d. None of the alternative answers is correct.
d. None of the alternative answers is correct.
The uniform probability distribution is used with a. a normally distributed random variable b. a discrete random variable c. any random variable d. a continuous random variable
d. a continuous random variable
In the set of all past due accounts, let the event A mean the account is between 31 and 60 days past due and the event B mean the account is that of a new customer. The union of A and B is a. all new customers b. all accounts fewer than 31 or more than 60 days past due c. all new customers whose accounts are between 31 and 60 days past due d. all accounts from new customers and all accounts that are from 31 to 60 days past due
d. all accounts from new customers and all accounts that are from 31 to 60 days past due
The t distribution is a family of similar probability distributions, with each individual distribution depending on a parameter known as the a. finite correction factor b. standard deviation c. sample size d. degrees of freedom
d. degrees of freedom
To compute the minimum sample size for an interval estimate of μ, we must first determine all of the following except a. population standard deviation b. desired margin of error c. confidence level d. degrees of freedom
d. degrees of freedom
The interquartile range is the difference between the a. first and second quartiles b. second and fourth quartiles c. second and third quartiles d. first and third quartiles
d. first and third quartiles
When using Excel to create a __________ one must edit the chart to remove the gaps between rectangles. a. bar chart b. scatter diagram c. pie chart d. histogram
d. histogram
The number of sick days taken (per month) by 200 factory workers is summarized below. Number of Days Frequency 0 − 5 120 6 − 10 65 11 − 15 14 16 − 20 1 The cumulative relative frequency for the class of 11 − 15 a. is 0.07 b. is 199 c. is 1 d. is 0.995
d. is 0.995
If the coefficient of correlation is 0.4, the percentage of variation in the dependent variable explained by the estimated regression equation a. can be any positive value b. is 4% c. is 40% d. is 16%
d. is 16%
The standard deviation of a standard normal distribution a. can be any value b. can be any positive value c. is always equal to zero d. is always equal to one
d. is always equal to one
A tabular summary of data showing the percentage of items in each of several non-overlapping classes is a a. frequency distribution b. cumulative percent frequency distribution c. relative frequency distribution d. percent frequency distribution
d. percent frequency distribution
A simple random sample of size n from a finite population of size N is to be selected. Each possible sample should have a. a probability of 1/n of being selected b. a probability of 1/N of being selected c. a probability of N/n of being selected d. the same probability of being selected
d. the same probability of being selected
As the goodness of fit for the estimated regression equation increases, a. the absolute value of the regression equation's slope increases b. the value of the regression equation's y intercept decreases c. the value of the correlation coefficient increases d. the value of the coefficient of determination increases
d. the value of the coefficient of determination increases
If two events are mutually exclusive, then the probability of their intersection a. can have any value larger than zero b. must be larger than zero, but less than one c. will be one d. will be equal to zero
d. will be equal to zero
Which of the following symbols represents the standard deviation of the population? a. x-bar b. μ c. σ^2 d. σ
d. σ
The expected value of the sample mean equals a. the mid-range of the population b. the mode of the population c. the median of the population d. the mean of the population
d. the mean of the population
One of the basic requirements of probability is
if there are k experiemental outcomes, the P(E1)+P(E2)+...+P(EK)=1
If P(A)=.50, P(B)=0.60, AND P(A ∩ B)=.30; then events A and B are
independent events
A list of all possible outcomes of an experiment is called a. the experimental outcome b. the likelihood set c. the sample space d. the sample point
the sample space
The probability of an event is
the sum of probabilities of the sample points in the event