A manufacturing company of tires claims the standard deviation of tire life is 4

Question

Explanation / Answer

a)
H0: sigma = 4000
H1: sigma < 4000

s = 3645.94
n = 16

Test statistics,
chi-square = (16-1)*(3645.94/4000)^2 = 12.4620

critical value of chi-square = 7.2609

As test statistics is greater than critical value, we fail to reject null hypothesis.

There are not significant evidence to conclude that std. dev. is less than 4000

b)
chi square value for upper bound = 7.2609

upper limit of CI = sqrt((16-1)*3645.94^2/7.2609) = 5240.3296

Hence the CI = (0, 5240.3296)

As 4000 is included in this CI, we fail to reject the null hypothesis.

There are not significant evidence to conclude that std. dev. is less than 4000

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.