In a survey, the favorite foods of respondents are identified as 1 for italian food comma 2 for mexican food comma 3 for chinese food comma and 4 for anything else. The average (mean) is calculated for 698 respondents and the result is 1.5 .

What is wrong with the given calculation?

A.

The true average? (mean) is

B.

Such data are not counts or measures of? anything, so the average? (mean) needs to be computed in a different way.

C.

Such data are not counts or measures of? anything, so it makes no sense to compute their average? (mean).

D.

There is nothing wrong with the given calculation.

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.