Ten years ago,only 20% of the U.S.population consisted of people more than 65 years old.A researcher plans to use a sample of n = 200 people to determine whether the population distribution has changed during the past ten years.If a chi-square test is used to evaluate the data,what is the expected frequency for the older-than-65 category?
A)10
B)20
C)40
D)100

Question

Quizplus · Accepted Answer

If 20% of the population was older than 65 ten years ago, then the expected frequency of the older-than-65 category in a sample of 200 people would be:

Expected frequency = (0.20) * 200 = 40

Therefore, the best choice is C.

Ten Years Ago,only 20% of the U