Question

Workers in a large plant are expected to complete a particular task in 60 seconds or less. The

production manager believes that the average worker is satisfying that expectation. To

examine the issue she watches eight workers perform the task and measures their times. The

times, which are assumed to be normally distributed, are 58, 53, 63, 62, 57, 55, 53, and 55.

Does this data provide sufficient evidence at the 5% significance level to support the

production manager’s belief?

a. Test statistics:

t

= 2.223

b. P-value= 1.895

c. Do not reject Ho. These data provide insufficient evidence at the 5% level of

significance to support the production manager’s belief.

d. Reject Ho. Yes, these data provide sufficient evidence at the 5% level of significance to

support the production manager’s belief.

Answer 1

	Values ( X )
	58	1
	53	16
	63	36
	62	25
	57	0
	55	4
	53	16
	55	4
Total	456	102

Mean

Standard deviation

To Test :-

H0 :-  

H1 :-

Test Statistic :-


t = -2.2228

Test Criteria :-
Reject null hypothesis if


Result :- Reject null hypothesis

P value = P ( t < - 2.228 ) = 0.0308

decision based on P value

Reject null hypothesis if P value < level of significance

P value = 0.0308 < 0.05, reject null hypothesis

Reject Ho. Yes, these data provide sufficient evidence at the 5% level of significance to

support the production manager’s belief.