Stats final

Suppose a life insurance company sells a $230,000 one-year term life insurance policy to a 20-year-old female for $210. The probability that the female survives the year is 0.999525. Compute and interpret the expected value of this policy to the insurance company. The expected value is $________ A. The insurance company expects to make an average profit of $ on every female it insures for 1 month. 9.16 20-year-old B. The insurance company expects to make an average profit of $ on every female it insures for 1 year. 209.90 20-year-old C. The insurance company expects to make an average profit of $ on every female it insures for 1 year. 100.75 20-year-old D. The insurance company expects to make an average profit of $ on every female it insures for 1 month.

$100.75 The insurance company expects to make an average profit of $100.75 on every 20-year-old female it insures for 1 year

Suppose a population has a mean of 7 for some characteristic of interest and a standard deviation of 9.6. A sample is drawn from this population of size 64. What is the standard error of the mean? A. 0.7 B. 3.3 C. 1.2 D. 0.15

1.2

Given that P(A or B)= 1/2, P(A)= 1/4, and P(A and B)= 1/7, find P(B). Express the probability as a simplified fraction. A) 17/28 B) 13/56 C) 25/28 D) 11/28

11/28

A market researcher randomly selects 500 homeowners under years of age and 500 homeowners over 30 years of age simple random stratified systematic convenience cluster

stratified

A man has 12 coins that consist of 3​ pennies, 4​ nickels, and 5 quarters. How many distinct arrangements of the coins can he make if he lays them in a row one at a​ time? A. ​479,001,600 B. ​27,720 .C. 9240 D. ​83,160

​27,720

The university police department keeps track of the number of tickets it write in a year. Last year the campus police wrote 1460 tickets. Ticket writing on campus follows a Poisson process. What is the mean number of tickets written per day by the campus​ police? 4 5 2 6.08

4

If A, B , C and D, are the only possible outcomes of an experiment, find the probability of D using the table below. Outcome: A, B, C, D Probability: 1/11, 1/11, 1/11 A. 8/11 B. 1/4 C. 3/11 D. 1/11

8/11

Which measure of central tendency is not resistant to extreme values in a numeric data​ set? Mode Parameters Mean Median

Mean

The distribution of salaries of professional basketball players is skewed to the right. Which measure of central tendency would be the best measure to determine the location of the center of the distribution? frequency mean median mode

Median

Identify the type of sampling used. At a local technical​ school, five auto repair classes are randomly selected and all of the students from each class are interviewed. simple random systematic cluster convenience stratified

cluster

Determine whether the quantitative variable is discrete or continuous. the low temperature in degrees Fahrenheit on January 1st in a certain city continuous discrete

continuous

Which terms are used to describe events that have no outcomes in common? A. independent or complements B. disjoint or mutually exclusive C. mutually exclusive or independent D. disjoint or independent

disjoint or mutually exclusive

Determine the level of measurement of the variable. a student's favorite sport A) ordinal B) ratio C) nominal D) Interval

nominal

The sample space for tossing three fair coins is {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT} What is the probability of exactly two heads? A) 1/2 B) 3/8 C) 5/8 D) 3

3/8

The sample space for tossing three fair coins is​ {HHH, HHT,​ HTH, HTT,​ THH, THT,​ TTH, TTT}. What is the probability of exactly two​ heads? A. 3/8 B. 1/2 C. 5/8 D. 3

3/8

The data below are the final exam scores of 10 randomly selected history students and the number of hours they slept the night before the exam. Find the equation of the regression line for the given data. What would be the predicted score for a history student who slept 15 hours the previous night? Is this a reasonable question? Round your predicted score to the nearest whole number. Round the regression line values to the nearest hundredth. Hours X- 3, 5, 2, 8, 2, 4, 4, 5, 6, 3 Scores Y- 65, 80, 60, 88, 66, 78, 85, 90, 90, 71 A) y= 5.04 x + 56.11; 132; yes, it is reasonable. B) y= -5.04 x + 56.11; -20; Yes, it is reasonable. C) y= -5.04 x + 56.11; -20, No, it is not reasonable. Fifteen hours is well outside the scope of the model. D) y= 5.04 x + 56.11; 132; No, it is not reasonable. Fifteen hours is well outside the scope of the model.

D) y= 5.04 x + 56.11; 132; No, it is not reasonable. Fifteen hours is well outside the scope of the model.

A severe drought affected several western states for 3 years. A holiday tree farmer is worried about the​ drought's effect on the size of his trees. To decide whether the growth of the trees has been​ retarded, the farmer decides to take a sample of the heights of 25 trees.​ Typically, trees of this age have a mean height of 65 inches with a standard deviation of 9 inches. Assuming the distribution is bell​ shaped, where would one expect the middle​ 95% of the tree heights to​ fall? over 56 inches tall between 47 and 83 inches tall between 38 and 92 inches tall between 56 and 74 inches tall

between 47 and 83 inches tall

The variable measured in an experiment is called​ _______. the response variable a sampling unit the predictor variable the treatment

the response variable

Suppose that E and F are two events and that P(E and F)= .22 and P(E)= .4. What is P(FIE)? Round to three decimal places. .62 .088 1.818 .55

.55

A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all​ students, the dean randomly selects 200 students and finds that 118 of them are receiving financial aid. Use a 95​% confidence interval to estimate the true proportion of students on financial aid. Express the answer in the form P±E and round to the nearest thousandth.

A. 0.59±0.005 B. 0.59s±0.002 C. 0.59±0.068 D. 0.59s±0.474

According to insurance records a car with a certain protection system will be recovered 94​% of the time. Find the probability that exactly 5 of 6 stolen cars will be recovered. Round to the nearest thousandth A- .833 B- .94 C- .06 D- .264

D- .264

(skewed left) C, B, A A B c Median, Mode, Mean

A= mode B= median C= mean

Researchers studied the mean egg length​ (in millimeters) for a bird population. After taking a random sample of​ eggs, they obtained a​ 95% confidence interval of​ (45,60). What is the value of the margin of​ error? A. 15 mm B. 1.96 C. 52.5 mm .D. 7.5 mm

7.5 mm

Identify the mean, median and mode C, B, A (skewed left)

A- Mode B- Median C- Mean

A quiz consists of 40 multiple choice​ questions, each with five possible​ answers, only one of which is correct. If a student guesses on each​ question, what is the mean and standard deviation of the number of correct​ answers? Round to the nearest thousandth. A. The mean is 8. The standard deviation is 2.53. .B. The mean is 20. The standard deviation is 2.53. C. The mean is 8. The standard deviation is 2.828. D. The mean is 20. The standard deviation is 4.472

A. The mean is 8. The standard deviation is 2.53.

Describe the sampling distribution of p. Round to three decimal places when necessary. N= 21,000 n= 200 p= .4 A. Approximately Normal. Mean- .4 SD- .035 B. Binomial. Mean- 80 SD- 6.923 C. Approximately Normal. Mean- .4 SD- .107 D. Exactly Normal. Mean- .4 SD- .035

A. Approximately Normal. Mean- .4 SD- .035

The data below are the final exam scores of 10 randomly selected history students and the number of hours they slept the night before the exam. Find the equation of the regression line for the given data. What would be the predicted score for a history student who slept 15 hours the previous​ night? Is this a reasonable​ question? Round your predicted score to the nearest whole number. Round the regression line values to the nearest hundredth. Hours x- 3, 5, 2, 8, 2, 4, 4, 5, 6, 3 Scores y- 65, 80, 60, 88, 66, 78, 85, 90, 90, 71 A. y= 5.04 x + 56.11; 132; No, it is not reasonable. Fifteen hours is well outside the scope of the model. B. y= -5.04 x + 56.11; -20; No, it is not reasonable. Fifteen hours is well outside the scope of the model. C. y= 5.04 x + 56.11; 132; Yes, it is reasonable D. y= -5.04 + 56.11; -20; Yes, it is reasonable.

A. y= 5.04 x + 56.11; 132; No, it is not reasonable. Fifteen hours is well outside the scope of the model.

Assuming that all conditions are met to approximate a binomial probability distribution with the standard normal​ distribution, then to compute P(x≥19) from the binomial distribution we must compute __ as the normal approximation. A. ​P(x≥​18.5) B. ​P(x≥​19.1) ​C. P(x≤​18.5) D. ​P(x≤​18.9)

A. ​P(x≥​18.5)

​Recently, the stock market took big swings up and down. A survey of 971 adult investors asked how often they tracked their portfolio. The table shows the investor responses. What is the probability that an adult investor tracks his or her portfolio​ daily? Express your answer as a simplified fraction and as a decimal rounded to three decimal places. How Frequently Response Daily 221 Weekly 273 Monthly 290 Couple Times a Year 134 Don't Track 53 A. 273/971: .281 B. 221/971: .228 C. 134/971: .138 D. 280/971: .299

B. 221/971: .228

Use the following frequency distribution to determine the class limits of the third class. 2-8 4 9-14 8 15-20 5 21-26 2 27-32 6 33-38 3 A) lower limit- 14, upper limit- 21 B) lower limit- 15, upper limit- 21 C) lower limit- 15, upper limit- 20 D) lower limit- 14.5, upper limit- 20.5

C) lower limit- 15, upper limit- 20

A group of realtors estimates that​ 23% of all homes purchased last year were considered investment properties. If a sample of 800 homes sold last year is​ obtained, what is the probability that at most 200 homes are going to be used as investment​ property? Round to four decimal places. A. 0.5935 B. 0.4066 C. 0.9099 D. 0.0901

C. 0.9099

Determine the area under the standard normal curve that lies between the following values. z=1 and z=3 A. 0.0007 B. 0.0004 C. 0.1574 D. 0.8426

C. 0.1574

Describe the sampling distribution of p. Round to three decimal places when necessary. N- 22,000, n- 500, p- .3 A. Binomial. Mean- 150, SD- 10.247 B. Exactly Normal. Mean- .3, SD- .020 C. Approximately Normal. Mean- .3, SD- .020 D. Approximately Normal: Mean- .3, SD- .098

C. Approximately Normal. Mean- .3, SD- .020

What is the normal density curve symmetric​ about? A. A point located one standard deviation from the mean B. The horizontal axis C. Its mean D. An inflection point

C. Its mean

A brewery has a beer dispensing machine that dispenses beer into the​ company's 12 ounce bottles. The distribution for the amount of beer dispensed by the machine follows a normal distribution with a standard deviation of 0.11 ounce. The company can control the mean amount of beer dispensed by the machine. What value of the mean should the company use if it wants to guarantee that​ 98.5% of the bottles contain at least 12 ounces​ (the amount on the​ label)? Round to the nearest thousandth. A. 12.267 oz B. 12.001 oz C. 12.002 oz D. 12.239 oz

D. 12.239 oz

Classify the following random variable as either discrete or continuous. The number of emails received on any given day Continuous, Discrete

Discrete

Compute​ P(x) using the binomial probability formula. Then determine whether the normal distribution can be used as an approximation for the binomial distribution. If​ so, approximate​ P(x) and compare the result to the exact probability. n =​80, p =0.7 x=62 ​(Round the standard deviation to three decimal places to work the​ problem.) ​A. Exact: 0.0343 Approximate: 0.0684 B. ​Exact: 0.0172 ​Approximate: 0.0342 C. ​Exact: 0.0172 Approximate: 0.0684 D. ​Exact: 0.0343 ​Approximate: 0.0342

Exact: 0.0343 ​Approximate: 0.0342

What does it mean if a statistic is​ resistant? A. Extreme values​ (very large or​ small) relative to the data affect its value substantially. B. Changing particular data values affects its value substantially. C. Extreme values​ (very large or​ small) relative to the data do not affect its value substantially. Your answer is correct.D. An estimate of its value is extremely close to its actual value.

Extreme values​ (very large or​ small) relative to the data do not affect its value substantially.

Suppose every student in a class is surveyed and it is found that​ 75% of the class plans to take another math class. It is reported that​ 75% of all students at the school plan to take another math class. Is this an example of descriptive or inferential​ statistics? Explain. A. Descriptive​ statistics; the results of the class sample are described without making any generalizations about the population of all students at the school. B. Inferential​ statistics; the results of the class sample are extended to make a generalization about the population of all students at the school. .C. Descriptive​ statistics; the results of the class sample are extended to make a generalization about the population of all students at the school. D. Inferential​ statistics; the results of the class sample are described without making any generalizations about the population of all students.

Inferential​ statistics; the results of the class sample are extended to make a generalization about the population of all students at the school.

In a normal​ distribution, approximately​ 68% of the area under the normal curve is within how many standard​ deviation(s) of the​ mean? ​One-half Two Three One

One

Determine the level of measurement of the variable. Weight of rice bought by a customer Interval Nominal Ratio Ordeal

Ratio

An anti-war advocate wants to estimate the percentage of people who favor cutting back of funds for the military. He conducts a nationwide survey of 1670 randomly selected adults 18 years and older. The interviewer asks the respondents. "Do you favor supporting peace by limiting our military involvement in world affairs?" A) Response Bias B) Sampling Bias C) Nonresponse

Response Bias

What​ factor(s) affect the accuracy of the sample mean as an estimate of the population​ mean? A. Variability only B. Sample size only .C. Sample size and variability D. Neither sample size nor variability affects the accuracy of this estimate.

Sample size and variability

Define statistics. A) Statistics is the science of collecting, organizing, summarizing, and analyzing information to draw a conclusion and answer questions. In addition, statistics is about providing a measure of confidence in any conclusions. B. Statistics encompasses all scientific disciplines in which percentages are used, data are analyzed, and probabilities are found. In addition, statistics references any mathematical model which is reported using percentages or proportions. C. Statistics is the science of manipulating, reorganizing, and editing information to produce the desired results. In addition, statistics is about providing the required answer with the desired level of confidence. D. Statistics encompasses all scientific disciplines in which random occurrences are analyzed. In addition, statistics references any random occurrence which is reported using percentages or proportions.

Statistics is the science of collecting, organizing, summarizing, and analyzing information to draw a conclusion and answer questions. In addition, statistics is about providing a measure of confidence in any conclusions.

An ogive is a graph that represents cumulative frequencies or cumulative relative frequencies. What are the points labeled on the horizontal axis? Midpoints Lower class limits Frequencies Upper class limits

Upper class limits

A traffic officer is compiling information about the relationship between the hour or the day and the speed over the limit at which the motorist is ticketed. He computes a correlation coefficient of 0.12. What does this tell the​ officer? A. There is insufficient evidence to make any conclusions about the relationship between the variables. B. There is a moderate positive linear correlation. C. There is a moderate negative linear correlation. D. There is a weak positive linear correlation.

There is a weak positive linear correlation

A frequency polygon always begins and ends with a frequency of zero. False True

True

Determine whether the statement is true or false. The class midpoint can be determined by adding to the lower class limit onehalf of the class width. False True

True

When choosing the sample size for estimating a population proportion p to within E units with confidence (1−α)100%, if you take p≈0.5 as the approximation to​ p, you will always obtain a sample size that is at least as large as required. True or False

True

Given the following least squares prediction equation, y= -173+74x, y is estimated to ______ by _____ with each 1-unit A. ​increase; 74 units B. ​increase; 173 units C. ​decrease; 74 units D. ​decrease; 173 units

increase; 74 units

A frequency distribution lists the (1) ____of occurrences of each category of data, while a relative frequency distribution lists the (2) ____of occurrences of each category of data. 1) proportion, number, percentage 2) proportion, number, total

number, proportion

If the coefficient of determination is close to​ 1, then A. the linear correlation coefficient is close to zero B. the sum of the square residuals is large compared to the total variation C. the least squares regression line equation explains most of the variation in the response variable .D. the least squares regression line equation has no explanatory value

the least squares regression line equation explains most of the variation in the response variable

The pie chart shows the percentage of votes received by each candidate in the student council presidential election. What percent of the votes did Lili and Gina receive together? Jim 32%, Gina 22%, Ming 27%, Lili 19% 59% 22% 41% 19%

41%

The pie chart shows the percentage of votes received by each candidate in the student council presidential election. What percent of the votes did Jim and Ben receive together? 600 total votes Ming- 29% Ben- 25% Jim- 20% Ann- 26% ​ 20% 55​% 25​% 45​%

45%

Assume that the heights of men are normally distributed with a mean of 68.5 inches and a standard deviation of 2.1 inches. If 36 men are randomly​ selected, find the probability that they have a mean height greater than 69.5 inches. Round to four decimal places. A. 0.0021 .B. 0.9979 C. 0.0210 D. 0.9005

.0021

The average score of all golfers for a particular course has a mean of 79 and a standard deviation of 5. Suppose 100 golfers played the course today. Find the probability that the average score of the 100 golfers exceeded 80. Round to four decimal places, .4772 .0228 .3707 .1293

.0228

The probability that a football game will go overtime is 10%. What is the probability that exactly two if three football games will go to into overtime? Round to the nearest thousandth. .1 .243 .027 .01

.027

A student answers all 48 questions on a multiplechoice test by guessing. Each question has four possible answers, only one of which is correct. Find the probability that the student gets exactly 15 correct answers. Use the normal distribution to approximate the binomial distribution. 0.0606 0.7967 0.8577 0.0823

.0823

Find the probability that in 200 tosses of a fair sixsided die, a three will be obtained at least 40 times. Round to four decimal places. 0.3875 0.1223 0.8810 0.0871

.1223

Find the area under the standard normal curve to the right of z = 1 0.1397 0.5398 0.1587 0.8413

.1587

Suppose that E and F are two events and that P(E)= .7 and P(FIIE)= 0.9. What is P(E and F)? Round to three decimal places. A) .630 B) .778 C) 1.600 D) .063

.630

High temperatures in a certain city for the month of August follow a uniform distribution over the interval 67 to 94 What is the probability that a randomly selected August day has a high temperature that exceeded 72 F 0.8148 0.037 0.1852 0.4472

.8148

The data below are the final exam scores of 10 randomly selected calculus students and the number of hours they slept the night before the exam. Calculate the linear correlation coefficient. Round to three decimal places. Hours, x: 1, 3, 0, 6, 0, 2, 2, 3, 4, 1 Scores, y: 60, 75, 55, 83, 61, 73, 80, 85, 66 A) .847 B) .991 C) .761 D) .654

.847

A group of realtors estimates that 23% of all homes purchased last year were considered investment properties. If a sample of 800 homes sold last year is obtained, what is the probability that at most 200 homes are going to be used as investment property? Round to four decimal places. A. 0.5935 B. 0.0901 C. 0.9099 D. 0.4066

.9099

A fair coin is tossed 5 times. What is the probability of at least one​ head? Round to the nearest​ ten-thousandth. .0313 .7500 .9688 .5000

.9688

The amount of corn chips dispensed into a 15​-ounce bag by the dispensing machine has been identified as possessing a normal distribution with a mean of 15.5 ounces and a standard deviation of 0.2 ounces. Suppose 400 bags of chips were randomly selected from this dispensing machine. Find the probability that the sample mean weight of these 400 bags exceeded 15.6 ounces. Round to four decimal places. A. 0.1915 B. 0.6915 C. 0.3085 .D. approximately 0

.D. approximately 0

A simple random sample of size n<30 has been obtained. From the​ boxplot, judge whether a​ t-interval should be constructed. A. ​No, there are no outliers but the data are not normally distributed. B. ​Yes, the data appear normally distributed and there are no outliers. C. ​No, there are outliers and the data are not normally distributed. .D. ​No, the data appear roughly normally distributed but there are outliers.

.D. ​No, the data appear roughly normally distributed but there are outliers.

Suppose a brewery has a filling machine that fills 12 ounce bottles of beer. It is known that the amount of beer poured by this filling machine follows a normal distribution with a mean of 12.21 ounces and a standard deviation of 0.04 ounce. Find the probability that the bottle contains fewer than 12.11 ounces of beer. 0.0062 0.9938 0.4938 0.5062

0.0062

According to a government​ commission, 70% of all the​ nation's households have VCRs. In a random sample of 15​ households, what is the probability that at least 13 have​ VCRs? Round to four decimal places. 0.5000 0.7000 0.8732 0.1268

0.1268

If the probability of a newborn kitten being female is​ 0.5, find the probability that in 100​ births, 55 or more will be female. Use the normal distribution to approximate the binomial distribution. 0.8159 0.1841 0.7967 0.0606

0.1841

A university must choose a team of 8 students to participate in a TV quiz show. The Students will be chosen from a pool of 30 potential participants of whom 13 are women. If the 8 students are chosen at random, what is the probability that the team will contain 3 women? Round to' four decimal places. A) .2663 B) .3326 C) .3024 D) .2929

0.3025

A group of realtors estimates that​ 23% of all homes purchased last year were considered investment properties. If a sample of 800 homes sold last year is​ obtained, what is the probability that at least 175 homes are going to be used as investment​ property? Round to four decimal places. A. 0.7764 B. 0.2236 C. 0.4821 D. 0.5189

0.7764

A fair coin is tossed 5 times. What is the probability of at least one head? Round to the nearest tenthousandth. A) .5000 B) .7500 C) .9688 D) .0313

0.9688

After constructing any relative frequency distribution, what should be the sum of the relative frequencies? 1 or 100% 0 the sample size the total of all class frequencies

1 or 100%

After constructing any relative frequency​ distribution, what should be the sum of the relative​ frequencies? the sample size 0 the total of all class frequencies 1 or​ 100%

1 or 100%

If p is the probability of a success of a binomial experiment, what is the probability of failure? x/n n/x 1-p -p

1-p

If p is the probability of success of a binomial​ experiment, what is the probability of​ failure? x/n n/x -p 1-p

1-p

A club elects a​ president, ​vice-​president, and​ secretary-treasurer. How many sets of officers are possible if there are 15 members and any member can be elected to each​ position? No person can hold more than one office. A. 32,760 B. 2,730 C. 1,365 .D. 910

2,730

Recently, the stock market took big swings up and down. A survey of 959 adult investors asked how often they tacked their portfolio. The table shows the investor responses. What is the probability that an adult investor tracks his or her portfolio daily? Express your answer as a simplified fraction and as a decimal rounded to three decimal places. How Frequently II Responses Daily 221 Weekly 261 Monthly 291 Couple times a year 132 Don't Track 54 A) 221/959; .230 B) 291/959; .303 C) 261/959; .272 D) 132/959; .138

221/959 .230

The following data are the​ yields, in​ bushels, of hay from a​ farmer's last 10 years. Find the IQR. ​375, 210,​ 150, 147,​ 429, 189,​ 320, 580,​ 407, 180 A. 265 B. 279 C. 253 D. 227

227

An insurance company crashed four cars in succession at 5 miles per hour. The cost of repair for each of the four crashes was $414, $456, $417, $229. Compute the range, sample variance, and sample standard deviation cost of repair The Range____ S^2______ s__________

227 10366 101.81

The following data represent the living situation of newlyweds in a large metropolitan area and their annual household income. What percent of people who rent their homemake between​ $35,000 and​ $50,000 per​ year? Round to the nearest thousandth of a percent. A) 20,000 B) 20-35,000 C) 35-50,000 D) 50-75,000 E) 75,000 Own Home: A) 31 B) 52 C) 202 D) 355 E) 524 Rent Home: A) 67 B) 66 C) 52 D) 23 E) 11 Live w/ Family: A) 89, 69, 30, 4, 2 A. 23.744% .B. 18.310​% C. 10.502​% D. 30.137​%

23.744%

A man has 12 coins that consist of 3 pennies, 4 nickels, and 5 quarters. How many distinct arrangements of the coins can he make if he lays them in a row one at a time? 83,160 9240 27,720 479,001,600

27,720

The data below are the temperatures on randomly chosen days during the summer in one city and the number of employee absences on those days for a company located in the same city. What is the best predicted value for y given x= 73? Round to the nearest whole number X- 72, 85, 91, 90, 88, 98, 75, 100, 80 Y- 3, 7, 10, 10, 8, 15, 4, 15, 5 A) 5 B) 4 C) 6 D) 3

3

The data represent the age of world leaders on their day of inauguration. Find the​ five-number summary, and construct a boxplot for the data. Comment on the shape of the distribution. 63, 64, 57, 59, 48, 69, 60, 47, 64, 45, 68, 56, 68, 62, 65 The Five Number Summary is: Create Boxplot Choose the correct description of the shape of the distribution. A. The distribution is skewed to the right. B. The distribution is skewed to the left.. C. The distribution is roughly symmetric. .D. The shape of the distribution cannot be determined from the boxplot.

45, 56, 62, 65, 59 The distribution is skewed to the left

The following data represent the monthly phone​ use, in​ minutes, of a customer enrolled in a fraud prevention program for the past 20 months. The phone company decides to use the upper fence as the cutoff point for the number of minutes at which the customer should be contacted. What is the cutoff​ point? 349, 351, 405, 534, 546, 439, 481, 481, 425, 317, 418, 370, 377, 544, 361, 537, 394, 345, 505, 431 The cutoff point is____

684

Calcul0ate the mean for the following discrete probability distribution. X- 1, 6, 7, 12 P(x)- 0.19, .17, 0.25, 0.39 1.91 7.64 5.62 26

7.64

Given that P(A or B)= 1/3, P(A)= 1/4, and P(A and B)= 1/9 find P(B). Express the probability as a simplified fraction. A. 25/36 B. 17/36 C. 4/27 D. 7/36

7/36

According to the government data, the probability that an adult was never in a museum is 15%. In a random survey of 10 adults, what is the probability that two or fewer were never in a museum? Round to the nearest thousandth. A) .820 B) .800 C) .200 D) .002

820

A club elects a president, vice-president, and secretary-treasurer. How many sets of officers are possible if there are 11 members and any member can be elected to each position? No person can hold more than one office. A. 330 B. 495 C. 7,920 D. 990

990

Explain the difference between a bar graph and a Pareto chart. A. A Pareto chart is always drawn with vertical​ bars, while a bar graph can be horizontal or vertical. B. A bar graph is used for qualitative​ data, and a Pareto chart is used for quantitative data. C. A Pareto chart is a particular type of bar graph in which the bars are touching and all the same width. D. A Pareto chart is a particular type of bar graph in which the bars are drawn in decreasing order of height.

A Pareto chart is a particular type of bar graph in which the bars are drawn in decreasing order of height.

Which of the following is a correct explanation of what a confidence interval​ is? A. A confidence interval gives an exact value for the population mean with a certain level of confidence. B. A confidence interval gives a range of possible values for the mean of those in the sample with a certain level of confidence. C. A confidence interval gives two values​ (called the lower bound and upper​ bound) that the population mean could be with a certain level of confidence. t.D. A confidence interval indicates how far off​ we're willing to be from the population mean with a certain level of confidence. E. A confidence interval is a range of values used to estimate the true value of a population parameter. The confidence level is the probability the interval actually contains the population​ parameter, assuming that the estimation process is repeated a large number of times.

A confidence interval is a range of values used to estimate the true value of a population parameter. The confidence level is the probability the interval actually contains the population​ parameter, assuming that the estimation process is repeated a large number of times.

The amount of money collected by a snack bar at a large university has been recorded daily for the past five years. Records indicate that the mean daily amount collected is $4,900 and the standard deviation is $300. The distribution is skewed to the right due to several high volume days​ (including football game​ days). Suppose that 100 days were randomly selected from the five years and the average amount collected from those days was recorded. Which of the following describes the sampling distribution of the sample​ mean? A. Normally distributed with a mean of $4,900 and a standard deviation of $30 B. Skewed to the right with a mean of $4,900 and a standard deviation of $300 C. Normally distributed with a mean of $4,900 and a standard deviation of$300 D. Normally distributed with a mean of $490 and a standard deviation of $ 30

A. Normally distributed with a mean of $4,900 and a standard deviation of $30

Determine whether the following normal probability plot indicates that the sample data could have come from a population that is normally distributed. NONLINEAR A. The normal probability plot does not indicate that the sample data could have come from a population that is normally distributed. B. The normal probability plot indicates that the sample data could have come from a population that is normally distributed.

A. The normal probability plot does not indicate that the sample data could have come from a population that is normally distributed.

Determine what type of observational study is described. Explain. A researcher wanted to determine whether colon cancer was associated with eating meat. He selected a sample of 500 men with colon cancer and an equal number of men without colon cancer. The two groups were similar in terms of​ age, occupation,​ income, and exercise levels. Histories on the amount of meat consumed over the previous twenty years were obtained for all men. The total amount of meat that each man eaten in the previous twenty years was estimated. The meat consumption was compared for the two groups. A. The observational study is a retrospective study because individuals are asked to look back in time. B. The observational study is a cohort study because individuals are observed over a long period of time. C. The observational study is a​ cross-sectional study because information is collected at a specific point in time.

A. The observational study is a retrospective study because individuals are asked to look back in time.

Compare a graph of the normal density function with a mean of 0 and standard deviation of 1 with a graph of a normal density function with a mean equal to 0 and standard deviation of 0.5. A. There would be no horizontal​ displacement, but the graph with a standard deviation of 1 would be flatter than the other. B. The graphs would have the same​ height, but the graph with a standard deviation of 1 would be shifted 4 units to the left. C. There would be no horizontal​ displacement, but the graph with a standard deviation of 1 would be steeper than the other. D. The graphs would have the same​ height, but the graph with a standard deviation of 1 would be shifted 4 units to the right.

A. There would be no horizontal​ displacement, but the graph with a standard deviation of 1 would be flatter than the other.

A random number generator is set to generate integer random numbers between 1 and 10 inclusive following a uniform distribution. What is the probability of the random number generator generating a 7 or​ less? A. 0.7 B. 0 C. 0.5 D. 0.07

A. 0.7

Assume that the random variable X is normally distributed with μ=80 and σ=14. Find the 96th percentile for X. A. 104.5 B. -16.5 C. 98.48 D. 91.62

A. 104.5

Describe the sampling distribution of p. Round to three decimal places when necessary. N= 17,000 n= 300 p=.3 Binomial: M= 90, SD= 7.937 Exactly Normal: M= .3, SD=.026 Approximately normal, M= .3 SD=.026 Approximately normal, M= .3, SD=0.111

Approximately normal, M= .3 SD=.026

A television station claims that the amount of advertising per hour of broadcast time has an average of 14 minutes and a standard deviation equal to 1.8 minutes. You watch the station for 1​ hour, at a randomly selected​ time, and carefully observe that the amount of advertising time is equal to 7 minutes. Calculate the​ z-score for this amount of advertising time. Round to two decimal places. A) z= 3.89 B) z= -3.89 C) .37 D) -.37

B) -3.89

Health care issues are receiving much attention in both academic and political arenas. A sociologist recently conducted a survey of senior citizens whose net worth is too high to qualify for government health care but who have no private health insurance. The ages of 25 uninsured senior citizens are listed below. Find Q1 of the data. 73, 78, 71, 81, 91, 79, 66, 94, 70, 95, 74, 97, 81, 67, 86, 68, 73, 86, 75, 78, 65, 92, 80, 69,87 A) 78.5 B) 70.5 C) 73 D) 68

B) 70.5

A student scores 62 on a geography test and 246 on a mathematics test. The geography test has a mean of 80 and a standard deviation of 15. The mathematics test has a mean of 300 and a standard deviation of 36. If the data for both tests are normally​ distributed, on which test did the student score better relative to the other students in each​ class? A) Relative to the other students in each class, the student scored better on the mathematics test B) Relative to the other students in each class, the student scored better on the geography test C) Relative to the other students in each class, the student scored the same on both tests

B) Relative to the other students in each class, the student scored better on the geography test

A survey of 250 households showed 74 owned at least one snow blower. Find a point estimate for​ p, the population proportion of households that own at least one snow blower. A. 0.42 B. 0.296 C. 0.704 D. 0.228

B. 0.296

An article a newspaper reported on the topics that teenagers most want to discuss with their parents. The​ findings, the results of a​ poll, showed that​ 46% would like more discussion about the​ family's financial​ situation, 37% would like to talk about​ school, and​ 30% would like to talk about religion. These and other percentages were based on a national sampling of 504 teenagers. Estimate the proportion of all teenagers who want more family discussions about school. Use a 98​% confidence level. Express the answer in the form P±E and round to the nearest thousandth. 0.63±0.050 B. 0.37±0.050 C 0.37±0.002 D. 0.63±0.002

B. 0.37±0.050

Which of the following statements is true about a normal density curve as σ ​increases? A. The curve becomes less spread out. B. The curve becomes more spread out. .C. There is no change in the spread of the curve. D. There is not enough information to determine the effect on the spread of the curve.

B. The curve becomes more spread out.

Construct a​ 95% confidence interval for the population​ mean, μ. Assume the population has a normal distribution. A sample of 25 randomly English majors has a mean test score of 81.5 with a standard deviation of 10.2. Round to the nearest hundredth. A. ​(66.35,69.89) B. ​(77.29,85.71) C. ​(87.12,98.32) D. ​(56.12,78.34)

B. ​(77.29,85.71)

Find the area under the standard normal curve between z=−1.5 and z=2.5. A. 0.7182 B. 0.9270 C. 0.9831 D. 0.6312

B. 0.9270

Suppose a population has a mean weight of 180 pounds and a standard deviation of 25 pounds. A sample of 100 items is drawn from this population. What is the standard error of the​ mean? A. 0.25 B. 2.5 C. 1.8 D. 18.0

B. 2.5

If the area to the left of a​ z-score is greater than​ 0.5, what must be​ true? A. The​ z-score must be equal to 0. B. The​ z-score must be positive. C. The​ z-score must be negative. .D. The​ z-score must be equal to 0.5.

B. The​ z-score must be positive.

Find the​ t-value such that the area in the right tail is 0.001 with 15 degrees of freedom. Round to the nearest thousandth. A. -3.733 B.3.733 C. 2.602 D. 3.787

B.3.733

A severe drought affected several western states for 3 years. A holiday tree farmer is worried about the drought's effect on the size of his trees. To decide whether the growth of the trees has been retarded, the farmer decides to take a sample of the heights of 25 trees. Typically, trees of this age have a mean height of 65 inches with a standard deviation of 9 inches. Assuming the distribution is bell shaped, where would one expect the middle 95% of the tree heights to fall? between 56 and 74 inches tall between 38 and 92 inches tall between 47 and 83 inches tall over 56 inches tall

Between 47 and 83 inches tall

What effect will an influential observation have upon the graph of the least squares regression​ line? A. It will push the graph away from the observation. B. It will have no effect. C. It will lower the value of the correlation coefficient to make further analysis meaningless. D. It will pull the graph toward the observation.

D. It will pull the graph toward the observation.

Define statistics. Choose the correct answer below. A. Statistics is the science of​ manipulating, reorganizing, and editing information to produce the desired results. In​ addition, statistics is about providing the required answer with the desired level of confidence. B. Statistics encompasses all scientific disciplines in which random occurrences are analyzed. In​ addition, statistics references any random occurrence which is reported using percentages or proportions. C. Statistics encompasses all scientific disciplines in which percentages are​ used, data are​ analyzed, and probabilities are found. In​ addition, statistics references any mathematical model which is reported using percentages or proportions. D. Statistics is the science of​ collecting, organizing,​ summarizing, and analyzing information to draw a conclusion and answer questions. In​ addition, statistics is about providing a measure of confidence in any conclusions.

D. Statistics is the science of​ collecting, organizing,​ summarizing, and analyzing information to draw a conclusion and answer questions. In​ addition, statistics is about providing a measure of confidence in any conclusions.

A sample of thirty users of a popular social networking site yielded the histogram on the right for the number of friends. What is the relationship between the mean and the median for this​ data? (It is skewed right) A. The mean and median will be roughly equal since the distribution is fairly symmetric. B. The mean will be substantially smaller than the median since the distribution is skewed left. C. The mean will be substantially smaller than the median since the distribution is skewed right. D. The mean will be substantially larger than the median since the distribution is skewed right.

D. The mean will be substantially larger than the median since the distribution is skewed right.

A doctor at a local hospital is interested in estimating the birth weight of infants. How large a sample must she select if she desires to be 95​% confident that her estimate is within 4 ounces of the true​ mean? Assume that s equals=6 ounces based on earlier studies. A. 3 B. 8 C. 2 D. 9

D. 9

Assuming that all conditions are met to approximate a binomial probability distribution with the standard normal​ distribution, then to compute P(x≥19) from the binomial distribution we must compute __ as the normal approximation. A. x > 19.1 B. x < 18.9 C. x < 18.5 D. x > 18.5

D. x > 18.5

A television station claims that the amount of advertising per hour of broadcast time has an average of 17 minutes and a standard deviation equal to 2.1 minutes. You watch the station for 1 hour, at a randomly selected time, and carefully observe that the amount of advertising time is equal to 11 minutes. Calculate the zscore for this amount of advertising time. Round to two decimal places. A) z= 2.86 B) z= -0.52 C) z= 0.52 D) z= -2.86

D. z=-2.86

The Multiplication Rule​ P(E and ​F)equals=​P(E) times •​P(F) applies only to which type of​ events? Dependent Complementary Disjoint Independent

Independent

Suppose a life insurance company sells a 190,000 one-year term life insurance policy to a 25-year-old female for $190. The probability that the female survives the year is .999584. Compute and interpret the expected value of this policy to the insurance company. The expected value: ____ Which of the following interpretation of the expected value is correct? A. The insurance company expects to make an average profit of ​$110.96 on every 25-year-old female it insures for 1 year. .B. The insurance company expects to make an average profit of 189.92 on every 25-year-old female it insures for 1 year. C. The insurance company expects to make an average profit of ​$10.09 on every 25-year-old female it insures for 1 month. D. The insurance company expects to make an average profit of ​$17.27 on every 25-year-old female it insures for 1 month

The insurance company expects to make an average profit of ​$10.09 on every 25-year-old female it insures for 1 month.

According to insurance records, a car with a certain protection system will be recovered 95% of the time. If 900 stolen cars randomly selected, what is the mean and standard deviation of the number of cars recovered after being stolen? Round to the nearest thousandth. A) The mean is 855. The standard deviation is 6.538. B) The mean is 855. The standard deviation is 42.75 C) The mean is 774. The standard deviation is 6.538 D) The mean is 774. The standard deviation is 42.75

The mean is 855. The standard deviation is 6.538.

A sample of thirty users of a popular social networking site yielded the histogram on the right for the number of friends. What is the relationship between the mean and the median for this data? (it is skewed right) A. The mean will be substantially smaller than the median since the distribution is skewed right. B. The mean will be substantially larger than the median since the distribution is skewed right. C. The mean and median will be roughly equal since the distribution is fairly symmetric. D. The mean will be substantially smaller than the median since the distribution is skewed left

The mean will be substantially larger than the median since the distribution is skewed right

When results from a scholastic assessment test are sent to​ test-takers, the percentiles associated with their scores are also given. Suppose a​ test-taker scored at the 59th percentile for their verbal grade and at the 26th percentile for their quantitative grade. Interpret these results. A. This student performed better than 41​% of the other​ test-takers in the verbal part and better than 26% in the quantitative part. B. This student performed better than 59​% of the other​ test-takers in the verbal part and better than 74​% in the quantitative part. C. This student performed better than 59​% of the other​ test-takers in the verbal part and better than 26% in the quantitative part. .D. This student performed better than 41​% of the other​ test-takers in the verbal part and better than 74​% in the quantitative part.

This student performed better than 59​% of the other​ test-takers in the verbal part and better than 26% in the quantitative part.

A national caterer determined that​ 87% of the people who sampled their food said that it was delicious. A random sample of 144 people is obtained from a population of 5000. The 144 people are asked to sample the​ caterer's food. Will the distribution of p, the sample proportion saying that the food is delicious, be approximately normal? Yes No

Yes

A study was designed to investigate the effects of two variables, (1) a student's level of mathematical anxiety and (2) teaching method, on a student's achievement in a mathematics course. Students who had a low level of mathematical anxiety were taught using the traditional expository method. These students obtained a mean score of 440 with a standard deviation 30 of on a standardized test. Assuming no information concerning the shape of the distribution is known, what percentage of the students scored between 380 and 500? A) at least 75% B) approximately 68% C) at least 88.9% D) approximately 95%

at least 75%

The _______ measures the percentage of total variation in the response variable that is explained by the least squares regression line. slope of the regression line coefficient of determination sum of the residuals squared coefficient of linear correlation

coefficient of determination

Determine whether the quantitative variable is discrete or continuous the number of goals scored in a hockey game continuous discrete

discrete

A frequency distribution lists the​ _________ of occurrences of each category of​ data, while a relative frequency distribution lists the​ _________ of occurrences of each category of data.

number, proportion

Classify the variable as qualitative or quantitative. the native languages of students in an English class qualitative quantitative

qualitative

the native languages of students in an English Class quantitative qualitative

qualititative

Compute the linear correlation coefficient between the two variables and determine whether a linear relation exists. Round to three decimal places. X- 9, 2, 3, 4, 2, 5, 9, 10 Y- 85, 52, 55, 68, 67, 86, 83, 73 A. r=​0.235; no linear relation exists B. r=​0.708; no linear relation exists C. . r= −​0.708; a linear relation exists D. r=​0.708; a linear relation exists

r=​0.708; no linear relation exists

According to the law of large​ numbers, as more observations are added to the​ sample, the difference between the sample mean and the population mean tends to become larger is inversely affected by the data added remains about the same tends to become smaller

tends to become smaller

A local bank needs information concerning the savings account balances of its customers. A random sample of 15 accounts was checked. The mean balance was​ $686.75 with a standard deviation of​ $256.20. Find a​ 98% confidence interval for the true mean. Assume that the account balances are normally distributed. Round to the nearest cent. A. ​($326.21,$437.90) B. ​($513.17,$860.33) .C. ​($487.31,$563.80) D. ​($238.23,$326.41)

​($513.17,$860.33)