Question

Assume that a computer or a calculator was used to generate the confidence interval, (0.802, 0.844) for the population proportion p, find the point estimate ˆp and the margin of error E.

Answer 1

Given confidence interval for proportion = ( 0.802 , 0.844)

Confidence interval for proportion in terms of and E is expressed as ( - E , + E)

Comparing these two intervals we get,

- E = 0.802, and + E = 0.844

Solve above two equation for and E,

Add both equations we get,

2 = 0.802 + 0.844

= 0.823

Put this value of in equation + E = 0.844 and solve for E

0.823 + E = 0.844

E = 0.844 - 0.823

E = 0.021

Therefore,

Point estimate = 0.823 and margin of error E = 0.021