Answer: 2.85
Explanation:
Given : A 90% confidence interval for the mean percentage of airline reservations being canceled on the day of the flight is (1.4, 4.3) .
We know that the the confidence interval for population mean
is given by :-
, where E is the margin of error.
Lower limit of confidence interval =
(1)
Upper limit of confidence interval =
(2)
Adding (1) and (2), we get

Hence, the point estimator of the mean percentage of reservations that are canceled on the day of the flight = 2.85