Question 1

In general, higher confidence levels provide _____.

Accepted Answer

A)  wider confidence intervals 
B)  narrower confidence intervals 
C)  a smaller standard error 
D)  unbiased estimates 
A)  wider confidence intervals 
B)  narrower confidence intervals 
C)  a smaller standard error 
D)  unbiased estimates

Question 2

It is known that the variance of a population equals 1,936. A random sample of 121 has been selected from the population. There is a .95 probability that the sample mean will provide a margin of error of _____.

Accepted Answer

A)  7.84 or less 
B)  31.36 or less 
C)  344.96 or less 
D)  1,936 or less 
A)  7.84 or less 
B)  31.36 or less 
C)  344.96 or less 
D)  1,936 or less

Question 3

When the level of confidence increases, the confidence interval _____.

Accepted Answer

A)  stays the same 
B)  becomes wider 
C)  becomes narrower 
D)  cannot be determined from the information given 
A)  stays the same 
B)  becomes wider 
C)  becomes narrower 
D)  cannot be determined from the information given

Question 4

A bank manager wishes to estimate the average waiting time for customers in line for tellers. A random sample of 50 times is measured and the average waiting time is 5.7 minutes. The population standard deviation of waiting time is 2 minutes. Which Excel function would be used to construct a confidence interval estimate?

Accepted Answer

A)  CONFIDENCE.NORM 
B)  NORM.INV 
C)  T.INV 
D)  INT 
A)  CONFIDENCE.NORM 
B)  NORM.INV 
C)  T.INV 
D)  INT

Question 5

A reporter for a student newspaper is writing an article on the cost of off-campus housing. A sample was selected of 10 one-bedroom units within a half-mile of campus and the rents paid. The sample mean is $550 and the sample standard deviation is $60.05. Provide a 95% confidence interval estimate of the mean rent per month for the population of one-bedroom units within a half-mile of campus. Assume this population is normally distributed.

Accepted Answer

We are 95% confident that the

Question 6

As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution _____.

Accepted Answer

A)  becomes larger 
B)  becomes smaller 
C)  stays the same 
D)  None of the answers is correct. 
A)  becomes larger 
B)  becomes smaller 
C)  stays the same 
D)  None of the answers is correct.

Question 7

If we change a 95% confidence interval estimate to a 99% confidence interval estimate, we can expect the _____.

Accepted Answer

A)  width of the confidence interval to increase 
B)  width of the confidence interval to decrease 
C)  width of the confidence interval to remain the same 
D)  sample size to increase 
A)  width of the confidence interval to increase 
B)  width of the confidence interval to decrease 
C)  width of the confidence interval to remain the same 
D)  sample size to increase

Question 8

An interval estimate is used to estimate _____.

Accepted Answer

A)  the shape of the population's distribution 
B)  the sampling distribution 
C)  a sample statistic 
D)  a population parameter 
A)  the shape of the population's distribution 
B)  the sampling distribution 
C)  a sample statistic 
D)  a population parameter

Question 9

The t value with a 95% confidence and 24 degrees of freedom is _____.

Accepted Answer

A)  1.711 
B)  2.064 
C)  2.492 
D)  2.069 
A)  1.711 
B)  2.064 
C)  2.492 
D)  2.069

Question 10

A marketing firm is developing a new television advertisement for a large discount retail chain. A sample of 30 people is shown two potential ads and asked their preference. The results for ad #1 follow. Use Excel to develop a 95% confidence interval estimate of the proportion of people in the population who will prefer ad #1. $\text { Prefer Advertis ement \# }$
$\begin{array}{llllll}
\text { yes } & \text { no } & \text { no } & \text { yes } & \text { yes } & \text { no } \
\text { no } & \text { no } & \text { no } & \text { yes } & \text { no } & \text { yes } \
\text { no } & \text { no } & \text { yes } & \text { yes } & \text { yes } & \text { no } \
\text { yes } & \text { yes } & \text { no } & \text { no } & \text { no } & \text { yes } \
\text { yes } & \text { no } & \text { yes } & \text { yes } & \text { no } & \text { no }
\end{array}$

Accepted Answer

The answer of A marketing firm is developing a new...

Question 11

A random sample of 144 observations has a mean of 20, a median of 21, and a mode of 22. The population standard deviation is known to equal 4.8. The 95.44% confidence interval for the population mean is _____.

Accepted Answer

A)  15.2 to 24.8 
B)  19.2 to 20.8 
C)  19.216 to 20.784 
D)  21.2 to 22.8 
A)  15.2 to 24.8 
B)  19.2 to 20.8 
C)  19.216 to 20.784 
D)  21.2 to 22.8

Question 12

In determining an interval estimate of a population mean when ? is unknown, we use a t distribution with _____ degrees of freedom.

Accepted Answer

A)  $\sqrt { n - 1 }$ 
B)  $\sqrt { n }$ 
C)  n ? 1 
D)  n 
A)  $\sqrt { n - 1 }$ 
B)  $\sqrt { n }$ 
C)  n ? 1 
D)  n

Question 13

The general form of an interval estimate of a population mean or population proportion is the _____ plus or minus the _____.

Accepted Answer

A)  population mean, standard error 
B)  level of significance, degrees of freedom 
C)  point estimate, margin of error 
D)  planning value, confidence coefficient 
A)  population mean, standard error 
B)  level of significance, degrees of freedom 
C)  point estimate, margin of error 
D)  planning value, confidence coefficient

Question 14

An estimate of a population parameter that provides an interval believed to contain the value of the parameter is known as the _____.

Accepted Answer

A)  confidence level 
B)  interval estimate 
C)  parameter value 
D)  population estimate 
A)  confidence level 
B)  interval estimate 
C)  parameter value 
D)  population estimate

Question 15

An auto manufacturer wants to estimate the annual income of owners of a particular model of automobile. A random sample of 200 current owners is selected. The population standard deviation is known. Which Excel function would NOT be appropriate to use to construct a confidence interval estimate?

Accepted Answer

A)  NORM.S.INV 
B)  COUNTIF 
C)  AVERAGE 
D)  STDEV 
A)  NORM.S.INV 
B)  COUNTIF 
C)  AVERAGE 
D)  STDEV

Question 16

To estimate a population mean, the sample size needed to provide a margin of error of 2 or less with a .95 probability when the population standard deviation equals 11 is _____.

Accepted Answer

A)  10 
B)  11 
C)  116 
D)  117 
A)  10 
B)  11 
C)  116 
D)  117

Question 17

It is known that the population variance equals 484. With a .95 probability, the sample size that needs to be taken to estimate the population mean if the desired margin of error is 5 or less is

Accepted Answer

A)  25 
B)  74 
C)  189 
D)  75 
A)  25 
B)  74 
C)  189 
D)  75

Question 18

The sample size that guarantees all estimates of proportions will meet the margin of error requirements is computed using a planning value of p equal to _____.

Accepted Answer

A)  .01 
B)  .50 
C)  .51 
D)  .99 
A)  .01 
B)  .50 
C)  .51 
D)  .99

Question 19

The mean of the t distribution is _____.

Accepted Answer

A)  0 
B)  .5 
C)  1 
D)  dependent upon the sample size 
A)  0 
B)  .5 
C)  1 
D)  dependent upon the sample size

Question 20

A local university administers a comprehensive examination to the recipients of a B.S. degree in Business Administration. A sample of five examinations is selected at random and scored. The scores are shown below. Grade
56
85
65
86
93 Use Excel to determine an interval estimate for the mean of the population at a 98% confidence level. Interpret your results.

Accepted Answer

​ @#IMG-DLM& Interpretation of Interval Estimate:

In general, higher confidence levels provide _____.

It is known that the variance of a population equals 1,936. A random sample of 121 has been selected from the population. There is a .95 probability that the sample mean will provide a margin of error of _____.

When the level of confidence increases, the confidence interval _____.

As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution _____.

If we change a 95% confidence interval estimate to a 99% confidence interval estimate, we can expect the _____.

An interval estimate is used to estimate _____.

The t value with a 95% confidence and 24 degrees of freedom is _____.

A random sample of 144 observations has a mean of 20, a median of 21, and a mode of 22. The population standard deviation is known to equal 4.8. The 95.44% confidence interval for the population mean is _____.

In determining an interval estimate of a population mean when ? is unknown, we use a t distribution with _____ degrees of freedom.

The general form of an interval estimate of a population mean or population proportion is the _ plus or minus the _.

An estimate of a population parameter that provides an interval believed to contain the value of the parameter is known as the _____.

An auto manufacturer wants to estimate the annual income of owners of a particular model of automobile. A random sample of 200 current owners is selected. The population standard deviation is known. Which Excel function would NOT be appropriate to use to construct a confidence interval estimate?

To estimate a population mean, the sample size needed to provide a margin of error of 2 or less with a .95 probability when the population standard deviation equals 11 is _____.

It is known that the population variance equals 484. With a .95 probability, the sample size that needs to be taken to estimate the population mean if the desired margin of error is 5 or less is

The sample size that guarantees all estimates of proportions will meet the margin of error requirements is computed using a planning value of p equal to _____.

The mean of the t distribution is _____.

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Tests of Goodness of Fit, Independence, and Multiple Proportions

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Time Series Analysis and Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Decision Analysis

Sample Survey

Filters

Exam 8: Interval Estimation

In general, higher confidence levels provide _____.

It is known that the variance of a population equals 1,936. A random sample of 121 has been selected from the population. There is a .95 probability that the sample mean will provide a margin of error of _____.

When the level of confidence increases, the confidence interval _____.

As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution _____.

If we change a 95% confidence interval estimate to a 99% confidence interval estimate, we can expect the _____.

An interval estimate is used to estimate _____.

The t value with a 95% confidence and 24 degrees of freedom is _____.

A random sample of 144 observations has a mean of 20, a median of 21, and a mode of 22. The population standard deviation is known to equal 4.8. The 95.44% confidence interval for the population mean is _____.

In determining an interval estimate of a population mean when ? is unknown, we use a t distribution with _____ degrees of freedom.

The general form of an interval estimate of a population mean or population proportion is the _____ plus or minus the _____.

An estimate of a population parameter that provides an interval believed to contain the value of the parameter is known as the _____.

An auto manufacturer wants to estimate the annual income of owners of a particular model of automobile. A random sample of 200 current owners is selected. The population standard deviation is known. Which Excel function would NOT be appropriate to use to construct a confidence interval estimate?

To estimate a population mean, the sample size needed to provide a margin of error of 2 or less with a .95 probability when the population standard deviation equals 11 is _____.

It is known that the population variance equals 484. With a .95 probability, the sample size that needs to be taken to estimate the population mean if the desired margin of error is 5 or less is

The sample size that guarantees all estimates of proportions will meet the margin of error requirements is computed using a planning value of p equal to _____.

The mean of the t distribution is _____.

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Tests of Goodness of Fit, Independence, and Multiple Proportions

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Time Series Analysis and Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Decision Analysis

Sample Survey

Filters

The general form of an interval estimate of a population mean or population proportion is the _ plus or minus the _.