Applied Statistics Help I dont understand this Please show w

Applied Statistics

Help. I dont understand this.. Please show work. Thank you!

Solution

(a) Since the students are chosen only from statistics class, the sampling method is not random. For college the subgroups will be the different departments and this method do not cover any subgroup other than Statistics. Thus the sample must be biased.

(b) Again in this case the sampling method is not random since only the students who joined the gymnastics were surveyed, while the population consists of all college women. Here the diifferent subgroups in college women will be divided on the basis of their workouts and since only those who have joined gymanstics are surveyed, all groups have not been covered. thus the sample must be biased.

(c)

In this case although it is not clear whether men have subscribed the magazine or not, but from the language if question it can be assumed that only women have subscribed the magazine. Also the assumption can be taken that the magazine is sold only in America. After these assumptions the process seems quite random, since any one can subscribe that magazine. Also there is no evidence of any particular group being favored for survey. Thus the sample can be assumed to be non-baised.

(d)

Since we have a random number generator the sampling method can be assumed to be random. Thus the sample should be non-biased.