A researcher selects a sample of 100 people to investigate the relationship between gender (male/female)and registering to vote.The sample consists of 40 females,of whom 30 are registered voters,and 60 males,of whom 40 are registered voters.If these data were used for a chi-square test for independence,what is the expected frequency for registered females?
A)12
B)28
C)40
D)42

Question

Quizplus · Accepted Answer

To determine the expected frequency for registered females, we need to first calculate the total number of registered voters in the sample. This is found by adding the number of registered females (30) to the number of registered males (40), for a total of 70 registered voters.

Next, we need to calculate the proportion of registered voters in the sample who are female. This is found by dividing the number of registered females by the total number of registered voters: 30/70 = 0.429.

To get the expected frequency for registered females, we multiply this proportion by the total sample size: 0.429 x 100 = 42.9, which we can round up to 43.

Therefore, the best choice is B, with an expected frequency of 43 registered females.

A Researcher Selects a Sample of 100 People to Investigate