To test whether the mean time to mix a batch of adhesive is the same for machines produced by four manufacturers. Data was obtained on time (minutes) needed to mix the materials. Test whether the machines have equal mean mixing time at alpha = 0.01.

a. None of the answers are correct.

b. The data provide strong evidence against H0: Equal means at pvalue 0.013. The mixing machines are not at all equal.

c. The data provide insignificant evidence against H0: Equal means at pvalue 0.514. The mixing machines are considered equal.

d. The data provide weak evidence against H0: Equal means at pvalue 0.072. Equality of means remains plausible.

e. The data provide extreme evidence against H0: Equal means at pvalue 0.001. The mixing machines are not all equal.

f. The pvalue 0.0001 is extreme evidence that the machines are not all the same.

Data:

Manufacturer

A B C D

25 23 25 22

23 21 25 23

21 23 25 23

23 24 21 22