QUESTION 4
The time a teenager requires driving (either in lessons and/or practice) before they pass the driving test is normally
distributed with a standard deviation of σ = 16 hours.
A sample of 4 teenage drivers finds that their mean time is x=65 hours
Find a 90% confidence interval and determine whether 80 hours is unusual.
Hint: This is a normal Z distribution
(Round to 1 dec. pl.)

Answer choices
a. (51,8, 78.1) so 80 is unusual
b. (37.9, 92.1) no 80 is not unusual
c. (51,8, 78.2) so 80 is not unusual
d. (51,8, 78.2) yes 80 is unusual