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 percentage change in bone mineral content (BMC) of the spines of 47 randomly selected mothers during three months of breast-feeding. The mean change in BMC was –3.587% and the standard deviation was 2.506%. The 99% confidence interval for the true mean percent change in BMC for breast-feeding mothers is (–4.569, –2.605).
Based on the confidence interval, do these data give convincing evidence that nursing mothers lose bone mineral, on average? Explain your answer.
A)No, the data do not give convincing evidence that breast-feeding mothers lose bone mineral, on average, because all of the values in the interval are less than zero.
B)Yes, the data give convincing evidence that breast-feeding mothers lose bone mineral, on average, because all of the plausible values in the interval are negative (indicating bone loss).
C)We are 99% confident that the interval from −4.569 to −2.605 captures the true mean percent change in BMC for breast-feeding mothers. Therefore, we know that nursing mothers gain bone mineral, on average.
D)We are 99% confident that the interval from −4.569 to −2.605 captures the true mean percent change in BMC for breast-feeding mothers. Because we are not 100% certain, there is not completely convincing evidence that all nursing mothers lose bone mineral, on average.
E)Even though all of the values in this interval are negative, this might not occur again in different samples. There is not enough evidence to make a conclusion regarding bone loss in breast-feeding mothers.
