Completely stuck

[kittysnyde]

I don't even know where to start on this question:

A 90% confidence interval for the mean percentage of airline reservations being canceled on the day of a the flight is (3.6%, 6.1%). What is the point estimator of the mean percentage of reservations that are canceled on the day of the flight?


The only thing I can think to do is:

find the difference between 6.1 and 3.6= 2.5

So you'd have: the point estimate +/- 2.5%

then divide that by 2 to give 1.25%

Then 6.1- 1.25 or 3.6 +1.25 = 4.85

?

 

[wjm11]

A 90% confidence interval for the mean percentage of airline reservations being canceled on the day of a the flight is (3.6%, 6.1%). What is the point estimator of the mean percentage of reservations that are canceled on the day of the flight?

The numbers given in a confidence interval represent the lowest and highest boundaries for the mean, with some percentage of "confidence." We think the mean is about in the middle of these two numbers, so the "point estimator of the mean" is the midpoint of the boundary numbers -- in other words, their average.

You arrived at the same conclusion by a slightly different logical approach.