confidence intervals

Question

determine the margin of error for the confidence interval for the mean 60< U<94

Answer 1

Hi Frank!

A confidence interval is calculated by adding and subtracting the Margin of Error from the mean.

This tells us the mean is the direct middle of the confidence interval. What is the middle of your interval? We can find this by averaging the lower limit and upper limit of the CI.

mean= (94+60)/2 = 77

Lower Limit = 77- Margin of Error

Upper Limit= 77 + Margin of Error

Last step: calculate the Margin of Error using either the upper or lower limit. Both should yield the same number:

94-77= 17

77-60= 17

Margin of Error= 17.

I hope this helps!