Question

Determine the point estimate of the population mean and margin of error for the confidence interval. Lower bound is 20?, upper bound is 30. The point estimate of the population mean is _____. The margin of error for the confidence interval is _____.

Answer 1

Given confidence interval is (20 , 30)

We express confidence interval in terms of sample mean and margin of error E as

( - E , + E)

Comparing this interval with given interval in question we get,

- E = 20 and + E = 30

Solve these two equations by adding together.

- E + + E = 20 + 30

2 = 50

= 25

Put this value of in equation + E = 30 and solve for E

25 + E = 30

E = 5

Sample mean is point estimate of population mean.

Therefore,

Point estimate of population mean is 25.

The margin of error for the confidence interval is 5