Breast-feeding mothers secrete calcium into their milk. Some of the calcium may come from their bones, so mothers may lose bone mineral. Researchers measured the percent change in mineral content of the spines of 47 mothers during three months of breast-feeding. Here are the data: -4.7 -2.5 -4.9 -2.7 -0.8 -5.3 -8.3 -2.1 -6.8 -4.3
2.2 -7.8 -3.1 -1.0 -6.5 -1.8 -5.2 -5.7 -7.0 -2.2
-6.5 -1.0 -3.0 -3.6 -5.2 -2.0 -2.1 -5.6 -4.4 -3.3
-4.0 -4.9 -4.7 -3.8 -5.9 -2.5 -0.3 -6.2 -6.8 1.7
0.3 -2.3 0.4 -5.3 0.2 -2.2 -5.1
A) The researchers are willing to consider these 47 women to be an SRS from the population of all nursing mothers. Suppose that the percent change in this population has standard deviation σ = 2.5%. Make a stemplot of the data to verify that the data follow a Normal distribution quite closely.
B) Use a 99% confidence interval to estimate the mean percent change in the population.