A SRS of 19 birth records at a local hospital was selected F

A SRS of 19 birth records at a local hospital was selected. For this sample, the average birth weight was 7.475 pounds. Assume that in the population of all babies born in this hospital, birth weight follows a Normal distribution with a standard deviation of 0.41 pounds.

sample size = 19, sample mean = 7.475, known standard deviation = 0.41, confidence level 95.0

1. What is the proper interpretation of the confidence interval in the context of the problem?

2. What is the margin of error of the confidence interval?

3. Change confidence to 90.0 = What is the margin of error of this confidence interval?

4. Change confidence to 99.0 = What is the margin of error of this confidence interval?

5. With all else being equal, how does increasing the confidence level affect the margin of error of a confidence interval?

Solution

1)
Confidence Interval
CI = x