Question

If the standard error of the mean is 2 and the critical values for 95% confidence interval is 1.96, compute the margin of error.

A) 1.96

B) 1.04

C) 2

D) 3.92

Using the margin of error from the previous question, compute the 95% confidence interval for a sample mean of 10.

A) 8 to 12

B) 8.96 to 11.04

C) 8.04 to 11.96

D) 6.08 to 13.92

Answer 1

Solution:

Question 1)

Margin of error = Critical value * Standard error = 1.96 * 2 = 3.92

Answer : 3.92

Option D is correct.

Question 2)

sample mean = 10

Margin of error = 3.92

The confidence interval is given by

Sample mean Margin of error

10 3.92

(10 - 3.92 , 10 + 3.92)

(6.08 , 13.92)

Answer :

6.08 to 13.92

Option D is correct.