Question 1

Skewness and kurtosis of a data set are measures of the shape of the distribution.

Accepted Answer

A) True 
 B)False  True

Question 2

The following box and whisker plot was constructed for the age of accounts receivable.   The box and whisker plot reveals that the accounts receivable ages are _______.

Accepted Answer

A)  skewed to the left 
B)  skewed to the right 
C)  not skewed 
D)  normally distributed 
E)  symmetrical 
A)  skewed to the left 
B)  skewed to the right 
C)  not skewed 
D)  normally distributed 
E)  symmetrical B

Question 3

The ages of the machines in one of the production lines in your company are exhibited in the frequency distribution table below.   What is the median age of these machines?

Accepted Answer

A)  2 
B)  3 
C)  3.5 
D)  4 
E)  4.5 
A)  2 
B)  3 
C)  3.5 
D)  4 
E)  4.5 D

Question 4

Computations of the variance and standard deviation using grouped data are potentially only approximation of the actual variance and standard deviation.

Accepted Answer

A) True 
 B)False

Question 5

A statistics student made the following grades on 7 tests: 76,82,92,95,79,86,and 92. What is the mean grade?

Accepted Answer

A)  78 
B)  80 
C)  86 
D)  84 
E)  88 
A)  78 
B)  80 
C)  86 
D)  84 
E)  88

Question 6

The ages of the machines in one of the production lines in your company are exhibited in the frequency distribution table below.   Two additional machines have been added to the production line,and the median age of the machines didn't change.
What is the minimum number of new (0-year-old)machines that you need to purchase to change the median age of the machines?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 7

Jessica Salas,president of Salas Products,is reviewing the warranty policy for her company's new model of automobile batteries. Life tests performed on a sample of 100 batteries indicated: (1)an average life of 75 months,(2)a standard deviation of 5 months,and (3)a bell shaped battery life distribution.Approximately 68% of the batteries will last between ________________.

Accepted Answer

A)  70 and 80 months 
B)  60 and 90 months 
C)  65 and 85 months 
D)  55 and 95 months 
E)  60 and 100 months 
A)  70 and 80 months 
B)  60 and 90 months 
C)  65 and 85 months 
D)  55 and 95 months 
E)  60 and 100 months

Question 8

A statistics student made the following grades on the first 6 tests: 76,82,92,95,92,86.The total number of tests for the semester is 7.If the median score for the whole semester was 92,what could not have been the score of the last test?

Accepted Answer

A)  77 
B)  92 
C)  93 
D)  94 
E)  96 
A)  77 
B)  92 
C)  93 
D)  94 
E)  96

Question 9

An instructor is evaluating the performance of students on a test. He records the number of points that each student missed and created a frequency distribution. This is provided below:   What is the variance for this population?

Accepted Answer

A)  11.43 
B)  135.17 
C)  130.67 
D)  180.67 
E)  198.07 
A)  11.43 
B)  135.17 
C)  130.67 
D)  180.67 
E)  198.07

Question 10

For grouped data,the midpoint of each class interval is used to represent all the values in a class interval.

Accepted Answer

A) True 
 B)False

Question 11

You have computed the z score for a value.Then you realize that the actual standard deviation of the population is 25% larger than the one you used for computing the z value.Your corrected z value will be _______.

Accepted Answer

A)  25% smaller than the original value 
B)  25% larger than the original value 
C)  75% smaller than the original value 
D)  20% larger than the original value 
E)  20% smaller than the original value 
A)  25% smaller than the original value 
B)  25% larger than the original value 
C)  75% smaller than the original value 
D)  20% larger than the original value 
E)  20% smaller than the original value

Question 12

A nonzero value of the skewness indicates asymmetry of the distribution of the data.

Accepted Answer

A) True 
 B)False

Question 13

The ages of students in a class have been put into the frequency distribution below.   What is the mode age of these students?

Accepted Answer

A)  18 
B)  19 
C)  20 
D)  21 
E)  23 
A)  18 
B)  19 
C)  20 
D)  21 
E)  23

Question 14

The average starting salary for graduates at a university is $33,000 with a standard deviation of $2,000. If a histogram of the data shows that it takes on a mound shape,the empirical rule says that approximately 68% of the graduates would have a starting salary between _______.

Accepted Answer

A)  29,000 and 37,000 
B)  27,000 and 39,000 
C)  25,000 and 41,000 
D)  29,000 and 37,000. 
E)  21,000 and 29,000 
A)  29,000 and 37,000 
B)  27,000 and 39,000 
C)  25,000 and 41,000 
D)  29,000 and 37,000. 
E)  21,000 and 29,000

Question 15

An appropriate measure of central tendency for ordinal data is the mode.

Accepted Answer

A) True 
 B)False

Question 16

A sample was taken of the salaries of four employees from a large company.The following are their salaries (in thousands of dollars)for this year: 33,36,41,and 47.The variance of their salaries is approximately

Accepted Answer

A)  28.19 
B)  75.59 
C)  37.58 
D)  6.13 
E)  5.31 
A)  28.19 
B)  75.59 
C)  37.58 
D)  6.13 
E)  5.31

Question 17

The mean life of a particular brand of light bulb is 1200 hours and the standard deviation is 75 hours. Tests show that the life of the bulb is approximately normally distributed. It can be concluded that approximately 68% of the bulbs will last between _______.

Accepted Answer

A)  900 and 1100 hours 
B)  950 and 1050 hours 
C)  975 and 1475 hours 
D)  1050 and 1350 hours 
E)  1125 and 1275 hours 
A)  900 and 1100 hours 
B)  950 and 1050 hours 
C)  975 and 1475 hours 
D)  1050 and 1350 hours 
E)  1125 and 1275 hours

Question 18

Pinky Bauer,Chief Financial Officer of Harrison Haulers,Inc.,suspects irregularities in the payroll system,and orders an inspection of "each and every payroll voucher issued since January 1,1993." Each payroll voucher was inspected and the following frequency distribution was compiled.   The mean number of errors per voucher is __________.

Accepted Answer

A)  3.67 
B)  5 
C)  750 
D)  300 
E)  8.7 
A)  3.67 
B)  5 
C)  750 
D)  300 
E)  8.7

Question 19

A commuter travels many miles to work each morning. She has timed this trip 5 times during the last month. The time (in minutes)required to make this trip was 34,39,41,35,and 41. The mean time (in minutes)required for this trip was _______.

Accepted Answer

A)  35 
B)  41 
C)  37.5 
D)  38 
E)  35.5 
A)  35 
B)  41 
C)  37.5 
D)  38 
E)  35.5

Question 20

A statistics student made the following grades on 7 tests: 76,82,92,95,79,86,and 92. What is the mode?

Accepted Answer

A)  79 
B)  82 
C)  86 
D)  92 
E)  76 
A)  79 
B)  82 
C)  86 
D)  92 
E)  76

Skewness and kurtosis of a data set are measures of the shape of the distribution.

The following box and whisker plot was constructed for the age of accounts receivable. The box and whisker plot reveals that the accounts receivable ages are _______.

The ages of the machines in one of the production lines in your company are exhibited in the frequency distribution table below. What is the median age of these machines?

Computations of the variance and standard deviation using grouped data are potentially only approximation of the actual variance and standard deviation.

A statistics student made the following grades on 7 tests: 76,82,92,95,79,86,and 92. What is the mean grade?

A statistics student made the following grades on the first 6 tests: 76,82,92,95,92,86.The total number of tests for the semester is 7.If the median score for the whole semester was 92,what could not have been the score of the last test?

An instructor is evaluating the performance of students on a test. He records the number of points that each student missed and created a frequency distribution. This is provided below: What is the variance for this population?

For grouped data,the midpoint of each class interval is used to represent all the values in a class interval.

You have computed the z score for a value.Then you realize that the actual standard deviation of the population is 25% larger than the one you used for computing the z value.Your corrected z value will be _______.

A nonzero value of the skewness indicates asymmetry of the distribution of the data.

The ages of students in a class have been put into the frequency distribution below. What is the mode age of these students?

The average starting salary for graduates at a university is $33,000 with a standard deviation of $2,000. If a histogram of the data shows that it takes on a mound shape,the empirical rule says that approximately 68% of the graduates would have a starting salary between _______.

An appropriate measure of central tendency for ordinal data is the mode.

A sample was taken of the salaries of four employees from a large company.The following are their salaries (in thousands of dollars)for this year: 33,36,41,and 47.The variance of their salaries is approximately

The mean life of a particular brand of light bulb is 1200 hours and the standard deviation is 75 hours. Tests show that the life of the bulb is approximately normally distributed. It can be concluded that approximately 68% of the bulbs will last between _______.

A commuter travels many miles to work each morning. She has timed this trip 5 times during the last month. The time (in minutes)required to make this trip was 34,39,41,35,and 41. The mean time (in minutes)required for this trip was _______.

A statistics student made the following grades on 7 tests: 76,82,92,95,79,86,and 92. What is the mode?

Introduction to Statistics

Charts and Graphs

Probability

Discrete Distributions

Continuous Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inference: Hypothesis Testing for Single Populations

Statistical Inferences About Two Populations

A Nalysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Building Multiple Regression Models

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

Exam 3: Descriptive Statistics

Skewness and kurtosis of a data set are measures of the shape of the distribution.

The following box and whisker plot was constructed for the age of accounts receivable. The box and whisker plot reveals that the accounts receivable ages are _______.

The ages of the machines in one of the production lines in your company are exhibited in the frequency distribution table below. What is the median age of these machines?

Computations of the variance and standard deviation using grouped data are potentially only approximation of the actual variance and standard deviation.

A statistics student made the following grades on 7 tests: 76,82,92,95,79,86,and 92. What is the mean grade?

A statistics student made the following grades on the first 6 tests: 76,82,92,95,92,86.The total number of tests for the semester is 7.If the median score for the whole semester was 92,what could not have been the score of the last test?

An instructor is evaluating the performance of students on a test. He records the number of points that each student missed and created a frequency distribution. This is provided below: What is the variance for this population?

For grouped data,the midpoint of each class interval is used to represent all the values in a class interval.

You have computed the z score for a value.Then you realize that the actual standard deviation of the population is 25% larger than the one you used for computing the z value.Your corrected z value will be _______.

A nonzero value of the skewness indicates asymmetry of the distribution of the data.

The ages of students in a class have been put into the frequency distribution below. What is the mode age of these students?

The average starting salary for graduates at a university is $33,000 with a standard deviation of $2,000. If a histogram of the data shows that it takes on a mound shape,the empirical rule says that approximately 68% of the graduates would have a starting salary between _______.

An appropriate measure of central tendency for ordinal data is the mode.

A sample was taken of the salaries of four employees from a large company.The following are their salaries (in thousands of dollars)for this year: 33,36,41,and 47.The variance of their salaries is approximately

The mean life of a particular brand of light bulb is 1200 hours and the standard deviation is 75 hours. Tests show that the life of the bulb is approximately normally distributed. It can be concluded that approximately 68% of the bulbs will last between _______.

A commuter travels many miles to work each morning. She has timed this trip 5 times during the last month. The time (in minutes)required to make this trip was 34,39,41,35,and 41. The mean time (in minutes)required for this trip was _______.

A statistics student made the following grades on 7 tests: 76,82,92,95,79,86,and 92. What is the mode?

Introduction to Statistics

Charts and Graphs

Probability

Discrete Distributions

Continuous Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inference: Hypothesis Testing for Single Populations

Statistical Inferences About Two Populations

A Nalysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Building Multiple Regression Models

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters