This info given - Breast-feeding mothers secrete calcium into their milk. Some of the calcium may come from their bones, so mothers may lose bone mineral. Previous research shows that the average percent change in mineral content for breast-feeding mothers is ? = ?4% with standard devi- ation ? = 2.5%. Researchers suspect that mothers who drink at least 8 ounces of milk per day while breastfeeding (milk-drinking mothers) lose less bone mineral. They measured the per- cent change in mineral content of the spines of 47 milk-drinking mothers during three months of breastfeeding. The data is contained in the Excel file that accompanies this worksheet.
(a) Make a histogram of the data (use class sizes of 1.5 or 2) to see that they appear to follow an approximately Normal distribution.
(b) Consider the question: Do milk-drinking mothers lose less bone mineral than all breast-feeding mothers? State the null and alternative hypotheses in terms of mean percent change ? in mineral content.
(c) Find the z test statistic.
(d) What is the P-value for your z?
(e) What do you conclude about the population of milk-drinking mothers?