In: Statistics and Probability
The administration at GSU wants to estimate the number of parking spaces they will need next year. They survey 80 students; 75 of the students in the sample drive to campus by themselves each day. Which of the following is a reason the administration should not calculate a confidence interval for the proportion of all students who drive to campus? Check all that apply. The sample needs to be random but we don’t know if it is. The actual count of drivers is too small. The actual count of those who do not drive to campus is too small. n ^ p is not greater than 10. n ( 1 − ^ p ) is not greater than 10.
Given,
sample size : n : Number of students surveyed = 80
Number of students drive themselves to campus by themselves.: x = 75
Number of students who don't driver = 80-75 = 5
Sample Proportion of students who drive to campus: = x/n = 75/80
n = (75/80)*80 = 75
n(1-) = n - n = 80 - 75=5
The sample needs to be random but we don’t know if it is -Yes
The actual count of drivers is too small - No ( as the count of drivers is 75 high enough)
The actual count of those who do not drive to campus is too small - Yes (count of those who do not drive to campus is 5 which is small)
n is not greater than 10 - No (as n = 75 which is greater than 10)
n(1-) is not greater than 10 - yes (as n(1-) = 5 which not greater than 10)