Body weight, high school girls. Body weights expressed as a percentage of ideal in an SRS of n = 9 girls selected at random are as follows {114, 100, 104, 94, 114, 105, 103, 105, 96}.

(a) Plot the data as a stemplot. (Use an axis multiplier of 10 and split stem values.) Are there any outliers or major departures from Normality in these data?

(b) Calculate a 95% confidence for population mean μ. Show all work.

(c) What is the margin of error of your confidence interval?

(d) How large a sample would be needed to reduce this margin of error to three?