Use the formula to calculate the lower and upper limits of the 90% confidence interval for a sample of N = 12 with a mean = 4.00 and standard error of the mean = .58.
A) (2.96, 5.04)
B) (2.20, 5.80)
C) 1.62, 6.38)
D) 2.72, 5.28)

Question

Use the formula  to calculate the lower and upper limits of the 90% confidence interval for a sample of N = 12 with a mean  = 4.00 and standard error of the mean  = .58.
A) (2.96, 5.04) 
B) (2.20, 5.80) 
C) 1.62, 6.38) 
D) 2.72, 5.28)

Quizplus · Accepted Answer

Using the formula, the lower limit of the 90% confidence interval can be calculated as:

4.00 - (1.833 * 0.58) = 2.96

And the upper limit can be calculated as:

4.00 + (1.833 * 0.58) = 5.04

Therefore, the 90% confidence interval is (2.96, 5.04). Choice A is the closest option to the calculated interval.

Use the Formula to Calculate the Lower and Upper