An SRS of 20 current birth records at the local hospital were chosen. In the sample, the average birth weight was 121.4 ounces and standard deviation was 7.5 ounces. Suppose that in the population of all babies born in this hospital, the birth weights follow a Normal distribution, with some mean ?.
Reference: Ref 17-1
We are interested in a 99% confidence interval for the population mean birth weight. The margin of error associated with the confidence interval is
A. 21.46 ounces.
B. 4.80 ounces.
C. 1.07 ounce.
D. 0.84 ounces.