In order to find out the probability that a student will bring acar to campus, 100 students are polled. Of those students, 85 havecars to bring to campus.
a) Find a point estimate for the proportion of students who willbring a car to campus.
b) For the 95% confidence level, find zc, the critical value forthe given confidence level.
c) For the 95% confidence level, find the error, E, for theconfidence interval (round your answer to two decimal places).
d) Find the 95% confidence interval for the proportion ofstudents who bring their car on campus.
e) Which of the following (1-4) is the correct interpretation ofthe confidence interval?
----1) We are 95% confident the proportion of students who willbring their car to campus is larger than .78.
----2) We are 95% confident the proportion of students who willbring their car to campus is between .78 and .92.
----3) We are 95% confident that the probability that a randomstudent will bring a car to campus is between .78 and .92.
----4) The proportion of students who will bring their cars tocampus is between .78 and .92.
f) The study that was done was a preliminary study and theschool will need to repeat the poll to get a 95% confidenceinterval. What should be the sample size in order for the error tobe less than .08?
