Stats Test One

During lunchtime, customers arrive at Bob's Drugs according to a Poisson distribution with on average 4 customers per minute. During a one minute interval, determine the following probability: no arrivals (keep 3 decimals)

0.018

Download the "FuelData08.xlsx" from the "ch2" folder in "Webfile" block, on Moodle, and answer the following question. How many Compact cars have Displacement value less than 5.5 (carefully group your Labels)? Answer: _______

81

A discrete probability distribution for which the relative frequency method is used to assign probabilities is the​ a. ​binomial distribution b. ​empirical discrete distribution c. ​hypergeometric distribution d. ​discrete uniform distribution

b. ​empirical discrete distribution

The number 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 Refer to Exhibit 2-1. The number of students who work 19 hours or less is Select one: a.80 b.100 c.200 d.400

b.100

The following is a frequency distribution of the monthly expenditures for long distance telephone service of 200 households in Chattanooga. Class Expenditure ($) # of households 1 0 and under 20. 42 2 20 and under 40 64 3 40 and under 60 34 4 60 and under 80 28 5 80 and under 100 20 6 100 and over 12 Refer to Exhibit 1-5. What is the cumulative relative frequency of the 2nd class? Select one: a. .32 b. .64 c. .36 d. .53

d. .53

A life insurance company has determined that the number of claims filed follows a Poisson distribution in its Nashville branch. On average, seven claims are filed per week. What is the probability that during the next week at least seventeen claims will be filed? (keep 3 decimals) a. 0.998 b. 0.002 c. 0.999 d. 0.001

d. 0.001

A life insurance company has determined that the number of claims filed follows a Poisson distribution in its Nashville branch. On average, seven claims are filed per week. What is the probability that during the next week there are either 4 or 5 claims will be filed? (keep 3 decimals) a. 0.091 b. 0.149 c. 0.128 d. 0.219

d. 0.219

Download the "PelicanStores.xlsx" from the "ch3" folder in "Webfile" block, on Moodle, and answer the following questions. Pelican stores, a division of National Clothing, is a chain of women's apparel stores operating throughout the country. The chain recently ran a promotion in which discount coupons were send to customers of other National Clothing stores. Data collected for a sample of 100 in-store credit card transactions at Pelican stores during one day. Customers who made a purchase using a discount coupon are referred to as promotional customers and the customers who made a purchase but did not use a discount coupon are referred as regular customers. The column "Items" indicates total number of items purchased. The column "Net Sales" records the total amount charged to the credit card. If we treat costumers who used a discount coupon as a sub sample, what is the z-score for the Net sales $198.8? (Keep 2 decimals) a. -0.55 b. 3.23 c. 2.36 d. 1.86

d. 1.86

x is a random variable with the probability function: f(x) = x/6 for x = 1,2 or 3. The expected value of x is a. 0.333 b. 0.500 c. 2.000 d. 2.333

d. 2.333

The following is a frequency distribution of the monthly expenditures for long distance telephone service of 200 households in Chattanooga. Class Expenditure ($) # of households 1 0 and under 20. 42 2 20 and under 40 64 3 40 and under 60 34 4 60 and under 80 28 5 80 and under 100 20 6 100 and over 12 Refer to Exhibit 1-5. What percentage of households have monthly expenditure for long distance service between $40 and $100? Select one: a. 54% b. 82% c. 27% d. 41%

d. 41%

As one of its major contributions, statistics uses data from a sample to make estimates and test hypotheses about the characteristics of a population through a process referred to as a. hypothesis of the sample b. descriptive statistics c. influencing the sample information d. statistical inference

d. statistical inference

The empirical rule states that, for data having a bell-shaped distribution, the percentage of data values being within two standard deviations of the mean is approximately​ a. ​65 b. ​75 c. ​85 d. ​95

d. ​95

A life insurance company has determined that the number of claims filed follows a Poisson distribution in its Nashville branch. On average, seven claims are filed per week. What is the probability that during the next week exactly seven claims will be filed? (keep 3 decimals)

0.149

A manufacturer of computer disk drives has a historical defective rate of .001. What is the probability that in a batch of 1000 drives, 2 would be defective? (keep 3 decimals) (hint: what is the number of trials? what is the 'success' rate?)

0.184

Download the "PelicanStores.xlsx" from the "ch3" folder in "Webfile" block, on Moodle, and answer the following questions. Pelican stores, a division of National Clothing, is a chain of women's apparel stores operating throughout the country. The chain recently ran a promotion in which discount coupons were send to customers of other National Clothing stores. Data collected for a sample of 100 in-store credit card transactions at Pelican stores during one day. Customers who made a purchase using a discount coupon are referred to as promotional customers and the customers who made a purchase but did not use a discount coupon are referred as regular customers. The column "Items" indicates total number of items purchased. The column "Net Sales" records the total amount charged to the credit card. You think the variable Net Sales isn't an accurate measurement, and you decide to look at the amount charged per item. So you calculate a new variable, Net Item Sales, which equals Net Sales divided by the number of Items sold. On average, the costumer who used a discount coupon spend how much LESS than the costumer who didn't use a discount coupon on every item they purchased? (round to integer) Please don't add dollar sign or comma.

10

The following table shows the starting salaries of a sample of recent business graduates. Income (In $1,000s) Number of Graduates 15 - 19 40 20 - 24 60 25 - 29 80 30 - 34 18 35 - 39 2 What percentage of graduates in the sample had starting salaries of at least $30,000? ______% (round to integer) Of the graduates in the sample, what percentage had starting salaries of less than $25,000? ______% (round to integer)

10% ; 50%

A sample of 9 mothers was taken. The mothers were asked the age of their oldest child. You are given their responses below. 3 12 4 7 14 6 2 9 11 The 75th percentile is (Please round to integer).

11

Download the "PelicanStores.xlsx" from the "ch3" folder in "Webfile" block, on Moodle, and answer the following questions. Pelican stores, a division of National Clothing, is a chain of women's apparel stores operating throughout the country. The chain recently ran a promotion in which discount coupons were send to customers of other National Clothing stores. Data collected for a sample of 100 in-store credit card transactions at Pelican stores during one day. Customers who made a purchase using a discount coupon are referred to as promotional customers and the customers who made a purchase but did not use a discount coupon are referred as regular customers. The column "Items" indicates total number of items purchased. The column "Net Sales" records the total amount charged to the credit card. On average, the customers who used a discount coupon spend how much more than the customers who didn't use a discount coupon. (round to integer) Please don't add dollar sign or comma.

22

Download the "PelicanStores.xlsx" from the "ch3" folder in "Webfile" block, on Moodle, and answer the following questions. Pelican stores, a division of National Clothing, is a chain of women's apparel stores operating throughout the country. The chain recently ran a promotion in which discount coupons were send to customers of other National Clothing stores. Data collected for a sample of 100 in-store credit card transactions at Pelican stores during one day. Customers who made a purchase using a discount coupon are referred to as promotional customers and the customers who made a purchase but did not use a discount coupon are referred as regular customers. The column "Items" indicates total number of items purchased. The column "Net Sales" records the total amount charged to the credit card. What is the sample standard deviation of variable Net Sales for Regular type of customer? (round to integer) Please don't add dollar sign or comma.

35

A sample of 9 mothers was taken. The mothers were asked the age of their oldest child. You are given their responses below. 3 12 4 7 14 6 2 9 11 The standard deviation of the sample is (Please keep two decimal places).(Please feel free to use excel)

4.22

A sample of 9 mothers was taken. The mothers were asked the age of their oldest child. You are given their responses below. 3 12 4 7 14 6 2 9 11 The mean of the sample is (Please keep two decimal places)

7.56

During lunchtime, customers arrive at Bob's Drugs according to a Poisson distribution with on average 4 customers per minute. During a one minute interval, determine the following probability: three or more arrivals. (keep 3 decimals) a. .762 b. .733 c. .147 d. .689

a. .762

During lunchtime, customers arrive at Bob's Drugs according to a Poisson distribution with on average 4 customers per minute. What is the probability of two arrivals in a two-minute period? (keep 3 decimals) a. 0.011 b. 0.016 c. 0.018 d. 0.07

a. 0.011

AMR is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below. Number of New Clients Probability 0 0.05 1 0.10 2 0.15 3 0.35 4 0.20 5 0.10 6 0.05 Refer to Exhibit 5-5. The standard deviation is a. 1.431 b. 2.047 c. 3.05 d. 21

a. 1.431

Download the "FuelData08.xlsx" from the "ch2" folder in "Webfile" block, on Moodle, and answer the following question. Among all Midsize cars, how many percent of Midsize cars have City MPG between 25 and 26, i.e equal either 25 or 26? (keep 1 decimal) a. 3.7% b. 5.1% c. 20.7% d. 2.5%

a. 3.7%

Download the "FuelData08.xlsx" from the "ch2" folder in "Webfile" block, on Moodle, and answer the following question. Among all cars have Hwy MPG between 25-29, i.e. equal 25, 26, 27, 28, or 29, how many percent of these cars are Large cars? (keep 1 decimal) a. 40.9% b. 55.2% c. 100% d. 67.1%

a. 40.9%

A researcher has collected the following sample data. 5 12 6 8 5 6 7 5 12 4 Refer to Exhibit 3-1. The sample variance is (please don't use computer to calculate this question) a. 8.22 b. 9.12 c. 6.20 d. 5

a. 8.22

If we only have the relative frequency table for the outcomes of a discrete random variable, Excel's __________ function can be used to compute the expected value of this discrete random variable. a. SUMPRODUCT b. AVERAGE c. MEDIAN d. VAR

a. SUMPRODUCT

Part of the data bank of a corporation is shown below. Employee Number Gender Department Years of Experience Employee Rank (1 - 10) Yearly Salary Refer to Exhibit 1-3. Employee Number is an example of ________ data. a. nominal b. ordinal c. interval d. ratio

a. nominal

Part of the data bank of a corporation is shown below. Employee Number Gender Department Years of Experience Employee Rank (1 - 10) Yearly Salary Refer to Exhibit 1-3. Gender is an example of ________ data. a. nominal b. ordinal c. interval d. ratio

a. nominal

Some hotels ask their guests to rate the hotel's services as excellent, very good, good, and poor. This is an example of the a. ordinal scale b. ratio scale c. nominal scale d. interval scale

a. ordinal scale

A random sample of 100 cars was selected from a population of 10,000 cars. Based upon that sample, the mean MPG of the cars was calculated determined to be 18. The mean based on this sample is called a a. sample statistic b. population parameter c. population survey d. sample census

a. sample statistic

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 Refer to Exhibit 5-2. The expected daily sales are a. $55,000 b. $56,000 c. $50,000 d. $70,000

b. $56,000

The probability that Pete will catch fish on a particular day when he goes fishing is 0.8. Pete is going fishing 3 days next week. Refer to Exhibit 5-10. The probability that Pete will catch fish on exactly one day is a. .008 b. .096 c. .104 d. .8

b. .096

The probability that Pete will catch fish on a particular day when he goes fishing is 0.8. Pete is going fishing 3 days next week. Refer to Exhibit 5-10. The variance of the number of days Pete will catch fish is a. .16 b. .48 c. .8 d. 2.4

b. .48

A life insurance company has determined that the number of claims filed follows a Poisson distribution in its Nashville branch. On average, seven claims are filed per week. What is the probability that during the next week fewer than four claims will be filed? (keep 3 decimals) a. 0.052 b. 0.082 c. 0.022 d. 0.091

b. 0.082

AMR is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below. Number of New Clients Probability 0 0.05 1 0.10 2 0.15 3 0.35 4 0.20 5 0.10 6 0.05 Refer to Exhibit 5-5. The variance is a. 1.431 b. 2.0475 c. 3.05 d. 21

b. 2.0475

A researcher has collected the following sample data. The mean of the sample is 5. 3 5 12 3 2 Refer to Exhibit 3-2. The coefficient of variation is a. 72.66% b. 81.24% c. 264% d. 330%

b. 81.24%

When using Excel's BINOM.DIST function, one should choose TRUE for the fourth input if a. a probability is desired b. a cumulative probability is desired c. the expected value is desired d. the correct answer is desired

b. a cumulative probability is desired

The variance of a sample of 81 observations equals 64. The standard deviation of the sample equals a. 0 b. 4096 c. 8 d. 6,561

c. 8

The summaries of data, which may be tabular, graphical, or numerical, are referred to as a. inferential statistics b. descriptive statistics c. statistical inference d. report generation

b. descriptive statistics

The number 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 Refer to Exhibit 2-1. The class width for this distribution Select one: a. is 9 b. is 10 c. is 39, which is: the largest value minus the smallest value or 39 - 0 = 39 d. varies from class to class

b. is 10

The number 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 Refer to Exhibit 2-1. The cumulative frequency for the class of 20 - 29 Select one: a. is 200 b. is 300 c. is 0.75 d. is 0.5

b. is 300

After the data has been arranged from smallest value to largest value, the value in the middle is called the a. range b. median c. mean d. None of the other answers are correct.

b. median

During a cold winter, the temperature stayed below zero for ten days (ranging from -20 to -5). The variance of the temperatures of the ten day period a. is negative since all the numbers are negative b. must be at least zero c. can not be computed since all the numbers are negative d. can be either negative or positive

b. must be at least zero

Five hundred residents of a city are polled to obtain information on voting intentions in an upcoming city election. The five hundred residents in this study is an example of a a. census b. sample c. observation d. population

b. sample

Excel's __________ function can be used to compute the median. Select one: a. MAX b. AVERAGE c. MEDIAN d. MODE

c. MEDIAN

Download the "PelicanStores.xlsx" from the "ch3" folder in "Webfile" block, on Moodle, and answer the following questions. Pelican stores, a division of National Clothing, is a chain of women's apparel stores operating throughout the country. The chain recently ran a promotion in which discount coupons were send to customers of other National Clothing stores. Data collected for a sample of 100 in-store credit card transactions at Pelican stores during one day. Customers who made a purchase using a discount coupon are referred to as promotional customers and the customers who made a purchase but did not use a discount coupon are referred as regular customers. The column "Items" indicates total number of items purchased. The column "Net Sales" records the total amount charged to the credit card. If we treat the 100 observations as a whole sample, what is the correlation between the variable Net Sales and the variable Age? (Keep 2 decimals) a. -7.33 b. -0.11 c. -0.01 d. 0

c. -0.01

A researcher has collected the following sample data. 5 12 6 8 5 6 7 5 12 4 Refer to Exhibit 3-1. What is the residual of the observation "4"? a. 3 b. 4 c. -3 d. -1

c. -3

The probability that Pete will catch fish on a particular day when he goes fishing is 0.8. Pete is going fishing 3 days next week. Refer to Exhibit 5-10. The probability that Pete will catch fish on one day or less is a. .008 b. .096 c. .104 d. .8

c. .104

A researcher has collected the following sample data. The mean of the sample is 5. 3 5 12 3 2 Refer to Exhibit 3-2. The range is a. 1 b. 2 c. 10 d. 12

c. 10

The probability that Pete will catch fish on a particular day when he goes fishing is 0.8. Pete is going fishing 3 days next week. Refer to Exhibit 5-10. The expected number of days Pete will catch fish is a. .6 b. .8 c. 2.4 d. 3

c. 2.4

Download the "PelicanStores.xlsx" from the "ch3" folder in "Webfile" block, on Moodle, and answer the following questions. Pelican stores, a division of National Clothing, is a chain of women's apparel stores operating throughout the country. The chain recently ran a promotion in which discount coupons were send to customers of other National Clothing stores. Data collected for a sample of 100 in-store credit card transactions at Pelican stores during one day. Customers who made a purchase using a discount coupon are referred to as promotional customers and the customers who made a purchase but did not use a discount coupon are referred as regular customers. The column "Items" indicates total number of items purchased. The column "Net Sales" records the total amount charged to the credit card. If we treat the 100 observations as a whole sample, what is the Coefficient of Variation of Age? a. 348% b. 45% c. 29% d. 356%

c. 29%

AMR is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below. Number of New Clients Probability 0 0.05 1 0.10 2 0.15 3 0.35 4 0.20 5 0.10 6 0.05 Refer to Exhibit 5-5. The expected number of new clients per month is a. 6 b. 0 c. 3.05 d. 21

c. 3.05

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

A frequency distribution is a. a tabular summary of a set of data showing the relative frequency b. a graphical form of representing data c. a tabular summary of a set of data showing the frequency of items in each of several nonoverlapping classes d. a graphical device for presenting categorical data Feedback

c. a tabular summary of a set of data showing the frequency of items in each of several nonoverlapping classes

The correlation coefficient a. is the same as the covariance b. can be larger than 1 c. cannot be larger than 1 d. cannot be negative

c. cannot be larger than 1

The total number of data items with a value less than the upper limit for the class is given by the a. frequency distribution b. relative frequency distribution c. cumulative frequency distribution d. cumulative relative frequency distribution

c. cumulative frequency distribution

A random variable that can assume only a finite number of values is referred to as a a. infinite sequence b. finite sequence c. discrete random variable d. discrete probability function

c. discrete random variable

Quantitative data refers to data obtained with a a. ordinal scale b. nominal scale c. either interval or ratio scale d. only interval scale

c. either interval or ratio scale

The number 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 Refer to Exhibit 2-1. The cumulative relative frequency for the class of 20 - 29 Select one: a. is 300 b. is 0.25 c. is 0.75 d. is 0.5

c. is 0.75

A population is a. the same as a sample b. the selection of a random sample c. the collection of all items of interest in a particular study d. always the same size as the sample

c. the collection of all items of interest in a particular study

Which of the following is not a characteristic of an experiment where the binomial probability distribution is applicable? a. the experiment has a sequence of n identical trials b. exactly two outcomes are possible on each trial c. the trials are dependent d. the probabilities of the outcomes do not change from one trial to another

c. the trials are dependent

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

Which of the following is not a required condition for a discrete probability function? a. f(x) ≥ 0 for all values of x b. ∑f(x) = 1 c. ∑f(x) = 0 d. All of the answers are correct.

c. ∑f(x) = 0

Download the "PelicanStores.xlsx" from the "ch3" folder in "Webfile" block, on Moodle, and answer the following questions. Pelican stores, a division of National Clothing, is a chain of women's apparel stores operating throughout the country. The chain recently ran a promotion in which discount coupons were send to customers of other National Clothing stores. Data collected for a sample of 100 in-store credit card transactions at Pelican stores during one day. Customers who made a purchase using a discount coupon are referred to as promotional customers and the customers who made a purchase but did not use a discount coupon are referred as regular customers. The column "Items" indicates total number of items purchased. The column "Net Sales" records the total amount charged to the credit card. What is the difference between the median of Net sales for married customers and the median of Net sales for single customers(round to integer) ? a. 2 b. 0 c. -2 d. 5

d. 5

In many universities, students evaluate their professors by means of answering a questionnaire. Assume a questionnaire is distributed to a class of 45 students. Students are asked to answer the following: 1. Sex 2. Race (Black, White, Other) 3. Age 4. Number of hours completed 5. Grade point average 6. My instructor is a very effective teacher 1 strongly agree 2 moderately agree 3 neutral 4 moderately disagree 5 strongly disagree Refer to Exhibit 1-4. How many variables are in this data set? Select one: a. 3 b. 4 c. 5 d. 6

d. 6

A researcher has collected the following sample data. 5 12 6 8 5 6 7 5 12 4 Refer to Exhibit 3-1. The 75th percentile is: (please don't use computer to calculate this question) a. 5 b. 6 c. 7 d. 8

d. 8

Excel's BINOM.DIST function can be used to compute a. bin width for histograms b. binomial probabilities c. cumulative binomial probabilities d. Both binomial probabilities and cumulative binomial probabilities are correct

d. Both binomial probabilities and cumulative binomial probabilities are correct

Excel's __________ function can be used to compute the sample correlation coefficient. Select one: a. MAX b. COVAR c. VAR d. CORREL

d. CORREL

Excel's __________ function can be used to compute the mode. Select one: a. MAX b. AVERAGE c. MEDIAN d. MODE.SNGL

d. MODE.SNGL