Unoccupied Seats on Flights Cause Airlines to Lose Revenue

Unoccupied seats on flights cause airlines to lose revenue.Suppose a large airline wants to estimate its average number of unoccupied seats per flight over the past year.225 flight records are randomly selected and the number of unoccupied seats is noted,with a sample mean of 11.6 seats and a standard deviation of 4.1 seats.Calculate a 90 percent confidence interval for μ,the mean number of unoccupied seats per flight during the past year.

A) [4.86,18.34]
B) [11.25,11.95]
C) [11.57,11.63]
D) [11.15,12.05]
E) [11.30,12.20]