Question

A 90% confidence interval for a proportion is found to be (0.52, 0.58). What isthe sample proportion?

Answer 1

A 90% confidence interval for a proportion is given as (0.52,0.58).

It is required to find the sample proportion.

Recall that for confidence interval (x,y), the sample proportion is the midpoint:

`c=(x+y)/(2)`

Substitute x=0.52 and y=0.58 into the equation:

`c=(0.52+0.58)/(2)=(1.1)/(2)=0.55`

The answer is C.