CitySearch

Multiple Choice

CitySearch.com reports that 55% of its users are in the 18-to-30 age demographic, 35% are in the 31-to-45 demographic, and the remaining 10% are in the 46-and-older demographic.In a recent survey of 200 randomly selected CitySearch.com users, 102 users were in the 18-to-30 age demographic, 84 were in the 31-to-45 demographic, and the rest were in the 46-and-older demographic. You conduct a chi-square test to determine whether this sample result is enough to reject a null hypothesis that the age group distribution of CitySearch.com users is as the website describes.If the null hypothesis is true, what is the expected number of users in the sample that would be in the 31-to-45 demographic?

A) 70
B) 72.2
C) 102
D) 84