week 4-5

Pretest

Directions: Identify the correct answer for each item. Write only the letter of your

choice.

1. What is the first step in hypothesis testing?

A. Choose the level of significance () and establish the rejection region.

B. Compute the value of the test statistic from the sample data.

C. Formulate the null and alternative hypotheses.

D. Select an appropriate test statistic and procedure.

2. If the critical value falls in the non-rejection region, then the null hypothesis ______.

A. cannot be rejected C. is rejected

B. cannot be determined D. is restated

3. Calculate the z-value given the following: hypothesis test on population mean;

x= 57; = 63; = 2; n = 45.

A. 20.12 B. 0.19 C. -20.12 D. -0.19

4. Calculate the t-value given the following: hypothesis test on population mean;

x= 35; = 33; s = 5; n = 25.

A. 2 B. 0.18 C. -2 D. -0.18

5. If H0: = 5.2; H1: > 5.2; = 0.01; z = 2.222, then the null hypothesis ________.

A. cannot be rejected C. is rejected

B. cannot be determined D. is restated

For items 6-10, consider the following situation.

Everyday Company has developed a new battery. The Engineering Department of

that company claims that each battery lasts for 180 minutes. To test this claim, the

company selects a random sample of 100 new batteries and this sample has a mean of

175 minutes with standard deviation of 25 minutes. Test the engineering department's

claim that the new batteries run with an average of 180 minutes. Uses = 0.05 level

of significance.

6. Which is the correct null hypothesis for the given problem?

A. H0: = 180 B. H0: 180 C. H0: > 180 D. H0: < 180

7. What type of statistical test is applicable for the given problem?

A. H-test B. t- test C. U-test D. z- test

8. What is the value of the applicable test statistic?

A. -2 B. -1.2 C. 1.2 D. 2

9. Which of the following is the critical region for a two-tailed test at = 0.05?

A. z < -1.96 or z > 1.96 C. z < -1.645 or z > 1.645

B. z < -2.33 or z > 2.33 D. z < -2.575 or z > 2.575

10. What should be the decision and conclusion for the given problem?

A. Reject the null hypothesis; therefore, there is no sufficient evidence to

suggest that the new batteries do not run an average of 180 minutes.

B. Reject the null hypothesis; therefore, there is sufficient evidence to suggest

that the new batteries do not run an average of 180 minutes.

C. Failed to reject the null hypothesis; therefore, there is no sufficient evidence

to suggest that the new batteries do not run an average of 180 minutes.

D. Failed to reject the null hypothesis; therefore, there is sufficient evidence to

suggest that the new batteries do not run an average of 180 minutes.

Activity 1

A. Directions: Solve for z-value or t-value based on the given information.

1. Hypothesis test on population mean; x= 657; = 663; = 12; n = 35

2. Hypothesis test on population mean; x= 24.35; = 28.46; s = 2.35; n = 25

B. Directions: Decide whether to reject or accept the null hypothesis based on the

given information.

1. H0: = 63,000; H1: > 63,000; = 0.01; z = 3.043

Decision:________________

2. H0: = 50; H1: 50; = 0.05; z = 1.697

CHECKING YOUR UNDERSTANDING

Directions: Perform hypothesis testing for the following problems.

1. Santos Farm takes pride in its poultry produce and claims that each dressed

chicken they sell provides 180 grams of protein. Test this claim at 0.01 level of

significance based on a random sample of 70 dressed chickens that yielded an

average of 176 grams of protein with sample standard deviation of 15 grams.

3. MLC claims that students who avail of their services get an average score of 385 on

scholastic aptitude test. The scores of random samples of 10 students were

recorded as follows: 350, 440, 350, 375, 400, 450, 475, 320, 300, 375. Use the level

of significance 0.01 to test whether the average of 385 is too high to claim.

POST TEST

Directions: Identify the correct answer for each item. Write only the letter of your

choice.

1. What is the second step in hypothesis testing?

A. Choose the level of significance () and establish the rejection region.

B. Compute the value of the test statistic from the sample data.

C. Formulate the null and alternative hypotheses.

D. Select an appropriate test statistic and procedure.

2. If the critical value falls in the rejection region, then the null hypothesis ______.

A. cannot be rejected C. is rejected

B. cannot be determined D. is restated

3. Calculate the z-value given the following: hypothesis test on population mean; x=

63; = 57; = 2; n = 45.

A. 20.12 B. 0.19 C. -20.12 D. -0.19

4. Calculate the t-value given the following: hypothesis test on population mean; x=

33; = 35; s = 5; n = 25.

A. 2 B. 0.18 C. -2 D. -0.18

5. If H0: =5.2; H1: > 5.2; = 0.05; z = 2.222, then the null hypothesis ________.

A. cannot be rejected C. is rejected

B. cannot be determined D. is restated

For items 6-10, consider the following situation.

Everyday Company has developed a new battery. The Engineering Department of

that company claims that each battery lasts for 180 minutes. To test this claim, the

company selects a random sample of 100 new batteries and this sample has mean of

183 minutes with standard deviation of 25 minutes. Test the engineering department's

claim that the new batteries run with an average of 180 minutes. Use = 0.01 level of

significance.

6. Which is the correct alternative hypothesis for the given problem?

A. H1: = 180 B. H1: 180 C. H1: > 180 D. H1: < 180

7. What type of test statistic is applicable for given problem?

A. H-test B. t- test C. U-test D. z- test

8. What is the value of the applicable test statistic?

A. -2 B. -1.2 C. 1.2 D. 2

9. Which of the following is the critical region for a two-tailed test at = 0.05?

A. z < -1.96 or z > 1.96 C. z < -1.645 or z > 1.645

B. z < -2.33 or z > 2.33 D. z < -2.575 or z > 2.575

10. What should be the decision and conclusion for the given problem?

A. Reject the null hypothesis; therefore, there is no sufficient evidence to

suggest that the new batteries do not run an average of 180 minutes.

B. Reject the null hypothesis; therefore, there is sufficient evidence to suggest

that the new batteries do not run an average of 180 minutes.

C. Failed to reject the null hypothesis; therefore, there is no sufficient evidence

to suggest that the new batteries do not run an average of 180 minutes.

D. Failed to reject the hypothesis; therefore, there is sufficient evidence to

suggest that the new batteries do not run an average of 180 minutes.