Question 1

In hypothesis testing, the tentative assumption about the population parameter is

Accepted Answer

A)  the alternative hypothesis 
B)  the null hypothesis 
C)  either the null or the alternative 
D)  None of these alternatives is correct. 
A)  the alternative hypothesis 
B)  the null hypothesis 
C)  either the null or the alternative 
D)  None of these alternatives is correct.

Question 2

In hypotheses testing,

Accepted Answer

A)  the sum of Type I and Type II errors must add up to 1 
B)  Type II is always twice as large as Type I error 
C)  the probability of Type I error is α 
D)  the probability of Type II error is β 
A)  the sum of Type I and Type II errors must add up to 1 
B)  Type II is always twice as large as Type I error 
C)  the probability of Type I error is α 
D)  the probability of Type II error is β

Question 3

The error of rejecting a true null hypothesis is

Accepted Answer

A)  a Type I error 
B)  a Type II error 
C)  is the same as β 
D)  committed when not enough information is available 
A)  a Type I error 
B)  a Type II error 
C)  is the same as β 
D)  committed when not enough information is available

Question 4

Exhibit 9-4
The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took the customers in the sample to check out was 3.1 minutes with a standard deviation of 0.5 minutes. We want to test to determine whether or not the mean waiting time of all customers is significantly more than 3 minutes.
-Refer to Exhibit 9-4. The p-value is between

Accepted Answer

A)  .005 to .01 
B)  .01 to .025 
C)  .025 to .05 
D)  .05 to .10 
A)  .005 to .01 
B)  .01 to .025 
C)  .025 to .05 
D)  .05 to .10

Question 5

The average life expectancy of tires produced by the Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of their tires has increased. In order to test the validity of their belief, the correct set of hypotheses is

Accepted Answer

A) H0: μ 40,000 C) H0: μ > 40,000 Ha: μ ≤ 40,000 D) H0: μ ≥ 40,000 Ha: μ < 40,000 A) H0: μ 40,000 C) H0: μ > 40,000 Ha: μ ≤ 40,000 D) H0: μ ≥ 40,000 Ha: μ < 40,000

Question 6

The average price of homes sold in the U.S. in the past year was $220,000. A random sample of 81 homes sold this year showed an average price of $210,000. It is known that the standard deviation of the population is $36,000. At 95% confidence test to determine if there has been a significant decrease in the average price homes.
a. State the null and alternative hypotheses to be tested.
b. Compute the test statistic.
c. Determine the critical value for this test.
d. What do you conclude?
e. Compute the p-value.

Accepted Answer

a. Ho: μ ≥ 220,000
Ha : μ < 22

Question 7

If a hypothesis is rejected at the 5% level of significance, it

Accepted Answer

A)  will always be rejected at the 1% level 
B)  will always be accepted at the 1% level 
C)  will never be tested at the 1% level 
D)  may be rejected or not rejected at the 1% level 
A)  will always be rejected at the 1% level 
B)  will always be accepted at the 1% level 
C)  will never be tested at the 1% level 
D)  may be rejected or not rejected at the 1% level

Question 8

The Department of Economic and Community Development DECD) reported that in 2009 the average number of new jobs created per county was 450. The department also provided the following information regarding a sample of 5 counties in 2010.
County New Jobs Created In 2010
Bradley 410
Rhea 480
Marion 407
Grundy 428
Sequatchie 400
a. Compute the sample average and the standard deviation for 2010.
b. We want to determine whether there has been a significant decrease in the average number of jobs created. Provide the null and the alternative hypotheses.
c. Compute the test statistic.
d. Compute the p-value; and at 95% confidence, test the hypotheses. Assume the population is normally distributed.

Accepted Answer

a. = 425 and s = 32.44 rounded

Question 9

Exhibit 9-8
The average gasoline price of one of the major oil companies in Europe has been $1.25 per liter. Recently, the company has undertaken several efficiency measures in order to reduce prices. Management is interested in determining whether their efficiency measures have actually reduced prices. A random sample of 49 of their gas stations is selected and the average price is determined to be $1.20 per liter. Furthermore, assume that the standard deviation of the population σ) is $0.14.
-Refer to Exhibit 9-8. The value of the test statistic for this hypothesis test is

Accepted Answer

A)  1.96 
B)  1.645 
C)  -2.5 
D)  -1.645 
A)  1.96 
B)  1.645 
C)  -2.5 
D)  -1.645

Question 10

The sum of the values of α and β

Accepted Answer

A)  always add up to 1.0 
B)  always add up to 0.5 
C)  is the probability of Type II error 
D)  none of these alternatives is correct 
A)  always add up to 1.0 
B)  always add up to 0.5 
C)  is the probability of Type II error 
D)  none of these alternatives is correct

Question 11

Two thousand numbers are selected randomly; 960 were even numbers.
a. State the hypotheses to determine whether the proportion of odd numbers is significantly different from 50%.
b. Compute the test statistic.
c. At 90% confidence using the p-value approach, test the hypotheses.

Accepted Answer

a. Ho: P = 0.5
Ha: P

Question 12

Consider the following hypothesis test:
Ho: p = 0.5
Ha: p ≠ 0.5
A sample of 800 provided a sample proportion of 0.58.
a. Determine the standard error of the proportion.
b. Compute the value of the test statistic.
c. Determine the p-value, and at 95% confidence, test the hypotheses.

Accepted Answer

a. 0.01768
b. Z = 4.

Question 13

In a lower one-tail hypothesis test situation, the p-value is determined to be 0.2. If the sample size for this test is 51, the t statistic has a value of

Accepted Answer

A)  0.849 
B)  -0.849 
C)  1.299 
D)  -1.299 
A)  0.849 
B)  -0.849 
C)  1.299 
D)  -1.299

Question 14

Exhibit 9-3
n = 49 = 54.8 s = 28 H0: μ ≤ 50
Ha: μ > 50
-Refer to Exhibit 9-3. The test statistic is

Accepted Answer

A)  0.1714 
B)  0.3849 
C)  -1.2 
D)  1.2 
A)  0.1714 
B)  0.3849 
C)  -1.2 
D)  1.2

Question 15

Exhibit 9-2
n = 64 = 50 s = 16 H0: μ ≥ 54
Ha: μ < 54
-Refer to Exhibit 9-2. The test statistic equals

Accepted Answer

A)  -4 
B)  -3 
C)  -2 
D)  -1 
A)  -4 
B)  -3 
C)  -2 
D)  -1

Question 16

For a one-tailed test lower tail) at 89.8% confidence, Z =

Accepted Answer

A)  -1.27 
B)  -1.53 
C)  -1.96 
D)  -1.64 
A)  -1.27 
B)  -1.53 
C)  -1.96 
D)  -1.64

Question 17

Exhibit 9-9
The sales of a grocery store had an average of $8,000 per day. The store introduced several advertising campaigns in order to increase sales. To determine whether or not the advertising campaigns have been effective in increasing sales, a sample of 64 days of sales was selected. It was found that the average was $8,300 per day.
From past information, it is known that the standard deviation of the population is $1,200.
-Refer to Exhibit 9-9. The value of the test statistic is

Accepted Answer

A)  250 
B)  8000 
C)  8250 
D)  2.0 
A)  250 
B)  8000 
C)  8250 
D)  2.0

Question 18

As the test statistic becomes larger, the p-value

Accepted Answer

A)  gets smaller 
B)  becomes larger 
C)  stays the same, since the sample size has not been changed 
D)  becomes negative 
A)  gets smaller 
B)  becomes larger 
C)  stays the same, since the sample size has not been changed 
D)  becomes negative

Question 19

If the level of significance of a hypothesis test is raised from .01 to .05, the probability of a Type II error

Accepted Answer

A)  will also increase from .01 to .05 
B)  will not change 
C)  will decrease 
D)  will increase 
A)  will also increase from .01 to .05 
B)  will not change 
C)  will decrease 
D)  will increase

Question 20

When the p-value is used for hypothesis testing, the null hypothesis is rejected if

Accepted Answer

A)  p­value ≤ α 
B)  α < p-value 
C)  p­value ≥ α 
D)  p-value = 1 - α 
A)  p­value ≤ α 
B)  α < p-value 
C)  p­value ≥ α 
D)  p-value = 1 - α

In hypothesis testing, the tentative assumption about the population parameter is

In hypotheses testing,

The error of rejecting a true null hypothesis is

The average life expectancy of tires produced by the Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of their tires has increased. In order to test the validity of their belief, the correct set of hypotheses is

If a hypothesis is rejected at the 5% level of significance, it

The sum of the values of α and β

Two thousand numbers are selected randomly; 960 were even numbers. a. State the hypotheses to determine whether the proportion of odd numbers is significantly different from 50%. b. Compute the test statistic. c. At 90% confidence using the p-value approach, test the hypotheses.

Consider the following hypothesis test: Ho: p = 0.5 Ha: p ≠ 0.5 A sample of 800 provided a sample proportion of 0.58. a. Determine the standard error of the proportion. b. Compute the value of the test statistic. c. Determine the p-value, and at 95% confidence, test the hypotheses.

In a lower one-tail hypothesis test situation, the p-value is determined to be 0.2. If the sample size for this test is 51, the t statistic has a value of

Exhibit 9-3 n = 49 = 54.8 s = 28 H0: μ ≤ 50 Ha: μ > 50 -Refer to Exhibit 9-3. The test statistic is

Exhibit 9-2 n = 64 = 50 s = 16 H0: μ ≥ 54 Ha: μ < 54 -Refer to Exhibit 9-2. The test statistic equals

For a one-tailed test lower tail) at 89.8% confidence, Z =

As the test statistic becomes larger, the p-value

If the level of significance of a hypothesis test is raised from .01 to .05, the probability of a Type II error

When the p-value is used for hypothesis testing, the null hypothesis is rejected if

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Exam 9: Hypothesis Tests

In hypothesis testing, the tentative assumption about the population parameter is

In hypotheses testing,

The error of rejecting a true null hypothesis is

The average life expectancy of tires produced by the Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of their tires has increased. In order to test the validity of their belief, the correct set of hypotheses is

If a hypothesis is rejected at the 5% level of significance, it

The sum of the values of α and β

Two thousand numbers are selected randomly; 960 were even numbers. a. State the hypotheses to determine whether the proportion of odd numbers is significantly different from 50%. b. Compute the test statistic. c. At 90% confidence using the p-value approach, test the hypotheses.

Consider the following hypothesis test: Ho: p = 0.5 Ha: p ≠ 0.5 A sample of 800 provided a sample proportion of 0.58. a. Determine the standard error of the proportion. b. Compute the value of the test statistic. c. Determine the p-value, and at 95% confidence, test the hypotheses.

In a lower one-tail hypothesis test situation, the p-value is determined to be 0.2. If the sample size for this test is 51, the t statistic has a value of

Exhibit 9-3 n = 49 = 54.8 s = 28 H0: μ ≤ 50 Ha: μ > 50 -Refer to Exhibit 9-3. The test statistic is

Exhibit 9-2 n = 64 = 50 s = 16 H0: μ ≥ 54 Ha: μ < 54 -Refer to Exhibit 9-2. The test statistic equals

For a one-tailed test lower tail) at 89.8% confidence, Z =

As the test statistic becomes larger, the p-value

If the level of significance of a hypothesis test is raised from .01 to .05, the probability of a Type II error

When the p-value is used for hypothesis testing, the null hypothesis is rejected if

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

Interval Estimation

Comparisons Involving Means, Experimental Design, and Analysis of Variance

Comparisons Involving Proportions and a Test of Independence

Simple Linear Regression

Multiple Regression

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