Question

A digital camcorder repair service has set a goal not to exceed an average of 5 working days from the time the unit is brought in to the time repairs are completed.

a) State the Hypothesis to show the goal is being met.

b) To test the hypothesis, the repair service takes a random sample of 12 repair records and recorded the repair time (in days). The data appear in the repair worksheet of the Hypothesis Tests HW data workbook on Moodle. Use JMP to test the hypothesis of part a).

c) Using  = 0.05, draw a conclusion for the hypothesis test. Make sure you state your conclusion in the context of the problem.

d) Use the PValue Animation in JMP to determine the smallest value that you can conclude the average repair time is less than at  = 0.05?

A digital camcorder repair service has set a goal not to exceed an average of 5 working days from the time the unit is brought in to the time repairs are completed.

a) State the Hypothesis to show the goal is being met.

b) To test the hypothesis, the repair service takes a random sample of 12 repair records and recorded the repair time (in days). The data appear in the repair worksheet of the Hypothesis Tests HW data workbook on Moodle. Use JMP to test the hypothesis of part a).

c) Using  = 0.05, draw a conclusion for the hypothesis test. Make sure you state your conclusion in the context of the problem.

d) Use the PValue Animation in JMP to determine the smallest value that you can conclude the average repair time is less than at  = 0.05?

Days

9

2

5

1

5

4

7

5

11

3

7

2

Answer 1

A) Use Z score test

NULL HYPOTHESIS:- goal not to exceed an average of 5 working days from the time the unit is brought in to the time repairs are completed.

ALTERNATIVE HYPOTHESIS:- goal to exceed an average of 5 working days from the time the unit is brought in to the time repairs are completed.

Z =      

Sample mean is 5.083

population mean is 5

standard deviation is 2.999

Z = 0.02776

c) calculated z score is 0.02776 is less than table value(1.96) of z table at 5 % significance level. The P-Value is .977901. so null hypothesis accepted and 97.79 % chance to complete the work in average 5 day.

d) p value is 0.0977901 . according to p value smallest determine value is 5.083. so, average repair time is less than at 0.05