Question 1

Hypotheses are tentative explanations of a principle operating in nature.

Accepted Answer

A) True 
 B)False  True

Question 2

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 -1.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

Accepted Answer

A) reject 
B) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate 
A) reject 
B) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate B

Question 3

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) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate 
A) reject 
B) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate A

Question 4

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 critical value of chi-square is ___.

Accepted Answer

A) 18.31 
B) 16.92 
C) 3.94 
D) 3.33 
E) 19.82 
A) 18.31 
B) 16.92 
C) 3.94 
D) 3.33 
E) 19.82

Question 5

The executives of CareFree Insurance Inc.feel that "a majority of our employees perceive a participatory management style at CareFree." A random sample of 200 CareFree employees is selected to test this hypothesis at the 0.05 level of significance.Eighty employees rate the management as participatory.The null hypothesis is ___.

Accepted Answer

A) n = 30 
B) n = 200 
C) p ≤ 0.50 
D) p  200 
A) n = 30 
B) n = 200 
C) p ≤ 0.50 
D) p  200

Question 6

In performing a hypothesis test where the null hypothesis is that the population mean is 6.9 against the alternative hypothesis that the population mean is not equal to 6.9, a random sample of 16 items is selected.The sample mean is 7.1 and the sample standard deviation is 2.4.It can be assumed that the population is normally distributed.The level of significance is selected as 0.05.The table "t" value for this problem is ___.

Accepted Answer

A) 1.753 
B) 2.947 
C) 2.120 
D) 2.131 
E) 2.311 
A) 1.753 
B) 2.947 
C) 2.120 
D) 2.131 
E) 2.311

Question 7

Consider the following null and alternative hypotheses. Ho: µ = 67
Ha: µ $\neq$67
These hypotheses ___.

Accepted Answer

A) indicate a one-tailed test with a rejection area in the right tail 
B) indicate a one-tailed test with a rejection area in the left tail 
C) indicate a two-tailed test 
D) are established incorrectly 
E) are not mutually exclusive 
A) indicate a one-tailed test with a rejection area in the right tail 
B) indicate a one-tailed test with a rejection area in the left tail 
C) indicate a two-tailed test 
D) are established incorrectly 
E) are not mutually exclusive

Question 8

If a null hypothesis was not rejected at the 0.10 level of significance, it will be rejected at a 0.05 level of significance based on the same sample results.

Accepted Answer

A) True 
 B)False

Question 9

Suppose you are testing the null hypothesis that a population mean is less than or equal to 80, against the alternative hypothesis that the population mean is greater than 80.The sample size is 49 and alpha =.05.If the sample mean is 84 and the population standard deviation is 14, the observed z value is ___.

Accepted Answer

A) 2 
B) -2 
C) 14 
D) -14 
E) 49 
A) 2 
B) -2 
C) 14 
D) -14 
E) 49

Question 10

In a two-tailed hypothesis about a population mean with a sample size of 100 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  1.645 
E) z  2.33 
A) z > 1.64 
B) z > 1.28 
C) z  1.28 
D) z  1.645 
E) z  2.33

Question 11

In testing hypotheses, the researcher initially assumes that the alternative hypothesis is true and uses the sample data to reject it.

Accepted Answer

A) True 
 B)False

Question 12

When a researcher fails to reject a false null hypothesis, a Type II error has been committed.

Accepted Answer

A) True 
 B)False

Question 13

In performing hypothesis tests about the population mean, the population standard deviation should be used if it is known.If it is not known, which of the following statistical test should be used?

Accepted Answer

A) z test of a population mean 
B) t test of a population mean 
C) z test of a population proportion 
D) $\chi$2 test of a population variance 
E) t test of a population proportion 
A) z test of a population mean 
B) t test of a population mean 
C) z test of a population proportion 
D) $\chi$2 test of a population variance 
E) t test of a population proportion

Question 14

In performing a hypothesis test where the null hypothesis is that the population mean is 23 against the alternative hypothesis that the population mean is not equal to 23, a random sample of 17 items is selected.The sample mean is 24.6 and the sample standard deviation is 3.3.It can be assumed that the population is normally distributed.The degrees of freedom associated with this are ___.

Accepted Answer

A) 17 
B) 16 
C) 15 
D) 2 
E) 1 
A) 17 
B) 16 
C) 15 
D) 2 
E) 1

Question 15

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$= .05 and a one-tailed test is 1.645.The observed z value from sample data is 1.13.The decision made by the researcher based on this information is to ___ the null hypothesis.

Accepted Answer

A) reject 
B) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate 
A) reject 
B) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate

Question 16

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 level of significance is selected to be 0.10.The table "t" value for this problem is ___.

Accepted Answer

A) 1.318 
B) 1.711 
C) 2.492 
D) 2.797 
E) 3.227 
A) 1.318 
B) 1.711 
C) 2.492 
D) 2.797 
E) 3.227

Question 17

Consider the following null and alternative hypotheses. Ho: µ  $\ge$ 67
Ha: µ < 67
These hypotheses ___.

Accepted Answer

A) indicate a one-tailed test with a rejection area in the right tail 
B) indicate a one-tailed test with a rejection area in the left tail 
C) indicate a two-tailed test 
D) are established incorrectly 
E) are not mutually exclusive 
A) indicate a one-tailed test with a rejection area in the right tail 
B) indicate a one-tailed test with a rejection area in the left tail 
C) indicate a two-tailed test 
D) are established incorrectly 
E) are not mutually exclusive

Question 18

Suppose the alternative hypothesis in a hypothesis test is "the population mean is greater than 60".If the sample size is 80 and alpha = .01, the critical value of z is ___.

Accepted Answer

A) 2.575 
B) -2.575 
C) 2.33 
D) -2.33 
E) 2.45 
A) 2.575 
B) -2.575 
C) 2.33 
D) -2.33 
E) 2.45

Question 19

In performing a hypothesis test where the null hypothesis is that the population mean is 6.9 against the alternative hypothesis that the population mean is not equal to 6.9, a random sample of 16 items is selected.The sample mean is 7.1 and the sample standard deviation is 2.4.It can be assumed that the population is normally distributed.The observed "t" value for this problem is ___.

Accepted Answer

A) 0.05 
B) 0.20 
C) 0.33 
D) 1.33 
E) 1.43 
A) 0.05 
B) 0.20 
C) 0.33 
D) 1.33 
E) 1.43

Question 20

The diameter of 3.5 centimetre discs is normally distributed.Periodically, quality control inspectors at Winnipeg Discs randomly select a sample of 16 discs.If the mean diameter of the discs is too large or too small the disc punch is shut down for adjustment; otherwise, the punching process continues.The last sample showed a mean and standard deviation of 3.49 and 0.08 centimetres, respectively.Using $\alpha$ = 0.05, the critical "t" values are ___.

Accepted Answer

A) -2.120 and 2.120 
B) -2.131 and 2.131 
C) -1.753 and 1.753 
D) -1.746 and 1.746 
E) -2.567 and 2.567 
A) -2.120 and 2.120 
B) -2.131 and 2.131 
C) -1.753 and 1.753 
D) -1.746 and 1.746 
E) -2.567 and 2.567

Hypotheses are tentative explanations of a principle operating in nature.

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 -1.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

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.

Consider the following null and alternative hypotheses. H_o: µ = 67 H_a: µ $\neq$ 67 These hypotheses ___.

If a null hypothesis was not rejected at the 0.10 level of significance, it will be rejected at a 0.05 level of significance based on the same sample results.

In a two-tailed hypothesis about a population mean with a sample size of 100 and alpha = 0.10, the rejection region would be ___.

In testing hypotheses, the researcher initially assumes that the alternative hypothesis is true and uses the sample data to reject it.

When a researcher fails to reject a false null hypothesis, a Type II error has been committed.

In performing hypothesis tests about the population mean, the population standard deviation should be used if it is known.If it is not known, which of the following statistical test should be used?

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a one-tailed test is 1.645.The observed z value from sample data is 1.13.The decision made by the researcher based on this information is to ___ the null hypothesis.

Consider the following null and alternative hypotheses. H_o: µ $\ge$ 67 H_a: µ < 67 These hypotheses ___.

Suppose the alternative hypothesis in a hypothesis test is "the population mean is greater than 60".If the sample size is 80 and alpha = .01, the critical value of z is ___.

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

Hypotheses are tentative explanations of a principle operating in nature.

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 -1.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

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.

Consider the following null and alternative hypotheses. Ho: µ = 67 Ha: µ ≠\neq= 67 These hypotheses ___.

If a null hypothesis was not rejected at the 0.10 level of significance, it will be rejected at a 0.05 level of significance based on the same sample results.

In a two-tailed hypothesis about a population mean with a sample size of 100 and alpha = 0.10, the rejection region would be ___.

In testing hypotheses, the researcher initially assumes that the alternative hypothesis is true and uses the sample data to reject it.

When a researcher fails to reject a false null hypothesis, a Type II error has been committed.

In performing hypothesis tests about the population mean, the population standard deviation should be used if it is known.If it is not known, which of the following statistical test should be used?

A researcher is testing a hypothesis of a single mean.The critical z value for α\alphaα = .05 and a one-tailed test is 1.645.The observed z value from sample data is 1.13.The decision made by the researcher based on this information is to ___ the null hypothesis.

Consider the following null and alternative hypotheses. Ho: µ ≥\ge≥ 67 Ha: µ < 67 These hypotheses ___.

Suppose the alternative hypothesis in a hypothesis test is "the population mean is greater than 60".If the sample size is 80 and alpha = .01, the critical value of z is ___.

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

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 -1.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

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.

Consider the following null and alternative hypotheses. H_o: µ = 67 H_a: µ $\neq$ 67 These hypotheses ___.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a one-tailed test is 1.645.The observed z value from sample data is 1.13.The decision made by the researcher based on this information is to ___ the null hypothesis.

Consider the following null and alternative hypotheses. H_o: µ $\ge$ 67 H_a: µ < 67 These hypotheses ___.