Question 1

Power is equal to (1 -$\beta$),the probability of a test rejecting the null hypothesis that is indeed false.

Accepted Answer

A) True 
 B)False

Question 2

David Desreumaux,VP of Human Resources of American First Banks (AFB),is reviewing the employee training programs of AFB banks.Based on a recent census of personnel,David knows that the variance of teller training time in the Southeast region is 8,and he wonders if the variance in the Southwest region is the same number.His staff randomly selected personnel files for 15 tellers in the Southwest Region,and determined that their mean training time was 25 hours and that the standard deviation was 4 hours.Assume that teller training time is normally distributed.Using $\alpha$ = 0.10,the appropriate decision is ________.

Accepted Answer

A) increase the sample size 
B) reduce the sample size 
C) fail to reject the null hypothesis 
D) maintain status quo 
E) reject the null hypothesis 
A) increase the sample size 
B) reduce the sample size 
C) fail to reject the null hypothesis 
D) maintain status quo 
E) reject the null hypothesis

Question 3

A coffee-dispensing machine is supposed to deliver 8 ounces of liquid into each paper cup,but a consumer believes that the actual mean amount is less.The consumer obtained a sample of 49 cups of the dispensed liquid with average of 7.75 ounces.If the sample variance of the dispensed liquid delivered per cup is 0.81 ounces,and α=0.05,the appropriate decision is ________.

Accepted Answer

A) increase the sample size 
B) reduce the sample size 
C) fail to reject the 8-ounces claim 
D) maintain status quo 
E) reject the 8-ounces claim 
A) increase the sample size 
B) reduce the sample size 
C) fail to reject the 8-ounces claim 
D) maintain status quo 
E) reject the 8-ounces claim

Question 4

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two?tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to _____ the null hypothesis.

Accepted Answer

A) reject 
B) fail to reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate the null hypothesis 
A) reject 
B) fail to reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate the null hypothesis

Question 5

The local oil changing business is very busy on Saturday mornings and is considering expanding.A national study of similar businesses reported the mean number of customers waiting to have their oil changed on Saturday morning is 3.6.Suppose the local oil changing business owner,wants to perform a hypothesis test.The null hypothesis is the population mean is 3.6 and the alternative hypothesis is the population mean is not equal to 3.6.The owner takes a random sample of 16 Saturday mornings during the past year and determines the sample mean is 4.2 and the sample standard deviation is 1.4.It can be assumed that the population is normally distributed.The level of significance is 0.05.The decision rule for this problem is to reject the null hypothesis if the observed "t" value is _______.

Accepted Answer

A) less than -2.131 or greater than 2.131 
B) less than -1.761 or greater than 1.761 
C) less than -1.753 or greater than 1.753 
D) less than -2.120 or greater than 2.120 
E) less than -3.120 or greater than 3.120 
A) less than -2.131 or greater than 2.131 
B) less than -1.761 or greater than 1.761 
C) less than -1.753 or greater than 1.753 
D) less than -2.120 or greater than 2.120 
E) less than -3.120 or greater than 3.120

Question 6

A recent survey suggests 30% of boat owners do not regularly use their boat after the second year of ownership.A local boat dealer wants to test the alternative hypothesis that p ≠ .30 with α = .05.He surveys 60 boat owners and finds 42% of the owners who have owned their boat for three years report they do not regularly use their boat.Assuming that p = .35,the probability of type II error is approximately

Accepted Answer

A) 0.8542 
B) 0.1458 
C) 0.3577 
D) 0.1423 
E) 0.4965 
A) 0.8542 
B) 0.1458 
C) 0.3577 
D) 0.1423 
E) 0.4965

Question 7

In testing a hypothesis about a population mean with an unknown population standard deviation ( $\sigma$ )the degrees of freedom is used in the denominator of the test statistic.

Accepted Answer

A) True 
 B)False

Question 8

In performing a hypothesis test where the null hypothesis is that the population mean is 4.8 against the alternative hypothesis that the population mean is not equal to 4.8,a random sample of 25 items is selected.The sample mean is 4.1 and the sample standard deviation is 1.4.It can be assumed that the population is normally distributed.The degrees of freedom associated with this are _______.

Accepted Answer

A) 25 
B) 24 
C) 26 
D) 2 
E) 1 
A) 25 
B) 24 
C) 26 
D) 2 
E) 1

Question 9

A company believes that it controls more than 30% of the total market share for one of its products.To prove this belief,a random sample of 144 purchases of this product is contacted.It is found that 50 of the 144 purchased this company's brand of the product.If a researcher wants to conduct a statistical test for this problem,the test would be _______.

Accepted Answer

A) a one-tailed test 
B) a two-tailed test 
C) an alpha test 
D) a finite population test 
E) a finite sample test 
A) a one-tailed test 
B) a two-tailed test 
C) an alpha test 
D) a finite population test 
E) a finite sample test

Question 10

In conducting z test of proportions,the sample proportion is computed by dividing the number of items being counted by the estimated total population.

Accepted Answer

A) True 
 B)False

Question 11

Business researchers sometimes need to test for equality of population variance.The hypothesis test about a population variance is performed using a chi-square test.

Accepted Answer

A) True 
 B)False

Question 12

Discrete Components,Inc.manufactures a line of electrical resistors.Presently,the carbon composition line is producing 100 ohm resistors.The population variance of these resistors "must not exceed 4" to conform to industry standards.Periodically,the quality control inspectors check for conformity by randomly select 10 resistors from the line,and calculating the sample variance.The last sample had a variance of 4.36.Assume that the population is normally distributed.Using $\alpha$ = 0.05,the appropriate decision is _________________.

Accepted Answer

A) increase the sample size 
B) reduce the sample size 
C) reject the null hypothesis 
D) fail to reject the null hypothesis 
E) maintain status quo 
A) increase the sample size 
B) reduce the sample size 
C) reject the null hypothesis 
D) fail to reject the null hypothesis 
E) maintain status quo

Question 13

A company believes that it controls more than 30% of the total market share for one of its products.To prove this belief,a random sample of 144 purchases of this product is contacted.It is found that 50 of the 144 purchased this company's brand of the product.If a researcher wants to conduct a statistical test for this problem,the observed z value would be _______.

Accepted Answer

A) 0.05 
B) 0.103 
C) 0.35 
D) 1.24 
E) 1.67 
A) 0.05 
B) 0.103 
C) 0.35 
D) 1.24 
E) 1.67

Question 14

The first step in testing a hypothesis is to establish a true null hypothesis and a false alternative hypothesis.

Accepted Answer

A) True 
 B)False

Question 15

In a two-tailed hypothesis about a population mean with a sample size of 100, $\sigma$ is known,and alpha = 0.10,the rejection region would be _______.

Accepted Answer

A) z > 1.64 
B) z > 1.28 
C) z  1.28 
D) z  1.64 
E) z  2.33 
A) z > 1.64 
B) z > 1.28 
C) z  1.28 
D) z  1.64 
E) z  2.33

Question 16

Elwin Osbourne,CIO at GFS,Inc.,suspects that at least 25% of e-mail messages sent by GFS employees are not business related.A random sample of 300 e-mail messages was selected to test this hypothesis at the 0.01 level of significance.Fifty-four of the messages were not business related.The appropriate decision is _______.

Accepted Answer

A) increase the sample size 
B) gather more data 
C) reject the null hypothesis 
D) fail to reject the null hypothesis 
E) maintain status quo 
A) increase the sample size 
B) gather more data 
C) reject the null hypothesis 
D) fail to reject the null hypothesis 
E) maintain status quo

Question 17

If a null hypothesis is not rejected at the 0.05 level of significance,the p-value is bigger than 0.05

Accepted Answer

A) True 
 B)False

Question 18

Whenever hypotheses are established such that the alternative hypothesis is "μ≠8",where μ is the population mean,the hypothesis test would be a two-tailed test.

Accepted Answer

A) True 
 B)False

Question 19

David Desreumaux,VP of Human Resources of American First Banks (AFB),is reviewing the employee training programs of AFB banks.Based on a recent census of personnel,David knows that the variance of teller training time in the Southeast region is 8,and he wonders if the variance in the Southwest region is the same number.His staff randomly selected personnel files for 15 tellers in the Southwest Region,and determined that their mean training time was 25 hours and that the standard deviation was 4 hours.Assume that teller training time is normally distributed.Using $\alpha$ = 0.10,the null hypothesis is ________.

Accepted Answer

A) $\mu$ = 25 
B)  $\sigma$2 = 8 
C)  $\sigma$2 = 4 
D)  $\sigma$2 $\le$ 8 
E) s2 = 16 
A) $\mu$ = 25 
B)  $\sigma$2 = 8 
C)  $\sigma$2 = 4 
D)  $\sigma$2 $\le$ 8 
E) s2 = 16

Question 20

Whenever hypotheses are established such that the alternative hypothesis is "μ>8",where μ is the population mean,the hypothesis test would be a two-tailed test.

Accepted Answer

A) True 
 B)False

Power is equal to (1 - $\beta$ ),the probability of a test rejecting the null hypothesis that is indeed false.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two?tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to _____ the null hypothesis.

In testing a hypothesis about a population mean with an unknown population standard deviation ( $\sigma$ )the degrees of freedom is used in the denominator of the test statistic.

In conducting z test of proportions,the sample proportion is computed by dividing the number of items being counted by the estimated total population.

Business researchers sometimes need to test for equality of population variance.The hypothesis test about a population variance is performed using a chi-square test.

The first step in testing a hypothesis is to establish a true null hypothesis and a false alternative hypothesis.

In a two-tailed hypothesis about a population mean with a sample size of 100, $\sigma$ is known,and alpha = 0.10,the rejection region would be _______.

If a null hypothesis is not rejected at the 0.05 level of significance,the p-value is bigger than 0.05

Whenever hypotheses are established such that the alternative hypothesis is "μ≠8",where μ is the population mean,the hypothesis test would be a two-tailed test.

Whenever hypotheses are established such that the alternative hypothesis is "μ>8",where μ is the population mean,the hypothesis test would be a two-tailed test.

Introduction to Statistics

Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Continuous Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inferences About Two Populations

Analysis 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 9: Statistical Inference: Hypothesis Testing for Single Populations

Power is equal to (1 - β\betaβ ),the probability of a test rejecting the null hypothesis that is indeed false.

A researcher is testing a hypothesis of a single mean.The critical z value for α\alphaα = .05 and a two?tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to _____ the null hypothesis.

In testing a hypothesis about a population mean with an unknown population standard deviation ( σ\sigmaσ )the degrees of freedom is used in the denominator of the test statistic.

In conducting z test of proportions,the sample proportion is computed by dividing the number of items being counted by the estimated total population.

Business researchers sometimes need to test for equality of population variance.The hypothesis test about a population variance is performed using a chi-square test.

The first step in testing a hypothesis is to establish a true null hypothesis and a false alternative hypothesis.

In a two-tailed hypothesis about a population mean with a sample size of 100, σ\sigmaσ is known,and alpha = 0.10,the rejection region would be _______.

If a null hypothesis is not rejected at the 0.05 level of significance,the p-value is bigger than 0.05

Whenever hypotheses are established such that the alternative hypothesis is "μ≠8",where μ is the population mean,the hypothesis test would be a two-tailed test.

Whenever hypotheses are established such that the alternative hypothesis is "μ>8",where μ is the population mean,the hypothesis test would be a two-tailed test.

Introduction to Statistics

Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Continuous Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inferences About Two Populations

Analysis 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

Power is equal to (1 - $\beta$ ),the probability of a test rejecting the null hypothesis that is indeed false.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two?tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to _____ the null hypothesis.

In testing a hypothesis about a population mean with an unknown population standard deviation ( $\sigma$ )the degrees of freedom is used in the denominator of the test statistic.

In a two-tailed hypothesis about a population mean with a sample size of 100, $\sigma$ is known,and alpha = 0.10,the rejection region would be _______.