birth weight of infants: a health care professional wishes to estimate the birth weights of infants. the researcher desires to be 99% confident that the true mean is within 2.5 ounces of the sample mean. the standard deviation of infant birth wieghts is known to be 7 ounces. show work

a.based on the information provided above, how large a sample must be obtained

b. if the resercher wanted to be 90% confident, how large should the sample size be

c. for which situation- a or b was the sample size, n, larger. explain why the calculated sample size was larger