400 UCF students were randomly selected and asked if they preferred washing their hands with soap and water or using hand sanitizer. 102 said they prefer to use hand sanitizer. 400 USF students were randomly selected and asked the same question. 112 said they prefer to use hand sanitizer. You want to examine the difference in the proportion of all UCF (1) and USF (2) students who prefer to use hand sanitizer. Which test should be used to determine if a difference exists between the proportion of all UCF and USF students who prefer to use hand sanitizer? a. z test for means
b. t test for means
c. z test for proportions
d. paired z test for means
e. paired t test for means