THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
Suppose two food preservatives are extensively tested and determined safe for use in meats.A processor wants to compare the preservatives for their effects on retarding spoilage.Suppose 16 cuts of fresh meat are treated with preservative A and another 12 cuts of meat are treated with preservative B.The number of hours until spoilage begins is recorded for each of the 28 cuts of meat.The results are summarized in the table below.

-What assumptions are necessary for a comparison of the population variances to be valid?
A)At least one of the population variances is known.
B)The samples are correlated.
C)One of the samples follows normal distribution and the other follows F distribution.
D)Both sampled populations are normally distributed.

Question

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
Suppose two food preservatives are extensively tested and determined safe for use in meats.A processor wants to compare the preservatives for their effects on retarding spoilage.Suppose 16 cuts of fresh meat are treated with preservative A and another 12 cuts of meat are treated with preservative B.The number of hours until spoilage begins is recorded for each of the 28 cuts of meat.The results are summarized in the table below.
 
-What assumptions are necessary for a comparison of the population variances to be valid?
A)At least one of the population variances is known. 
B)The samples are correlated. 
C)One of the samples follows normal distribution and the other follows F distribution. 
D)Both sampled populations are normally distributed.

Quizplus · Accepted Answer

The assumption necessary for a comparison of population variances to be valid is that both sampled populations are normally distributed. Choice A is incorrect because it assumes that at least one population variance is known, which is not necessary. Choice B is incorrect because it assumes that the samples are correlated, which is not specified in the problem. Choice C is incorrect because it assumes that one sample follows a normal distribution and the other follows an F distribution, which is not applicable here.