Suppose you are conducting a study to determine if women are better drivers than men.You send your survey to over 1000 students on your campus and 5 students respond that women are better drivers and 4 students respond that women are not better drivers. What is the sample proportion

for women as the better drivers using the plus four method?

A) 5/9
B) 7/13
C) 9/13
D) None of the above

The plus four method adds 2 to the number of responses in each category (in this case, 5+2 and 4+2) before dividing by the total number of responses (9+4). So the calculations would be:

Women are better drivers: (5+2)/(9+4) = 7/13
Women are not better drivers: (4+2)/(9+4) = 6/13

Therefore, the sample proportion for women as the better drivers using the plus four method is 7/13. Choice B is the correct answer.