Twenty-five patients of a certain diagnosis-related group were randomly selected, and their systolic blood pressure, blood glucose level, and total cholesterol level were measured. Upon administration of a certain drug, after 6 months the same characteristics were measured for the selected patients. The data are shown in given Table.
(a) Find the mean, standard deviation, skew ness coefficient, kurtosis coefficient, and interquartile range of systolic blood pressure before the drug was administered and comment on the values.
(b) Find the mean, standard deviation, skew ness coefficient, kurtosis coefficient, and interquartile range of systolic blood pressure after the drug was administered and comment on the values.
(c) Can we conclude that the mean systolic blood pressure before the drug was administered exceeds 125? Use α = 0.05. What is the p-value?
(d) Can we conclude that the drug was effective in reducing mean systolic blood pressure? Use α = 0.05. What is the p-value? Explain this p-value.
(e) Did the drug have a significant impact on reducing the average cholesterol level? Use α = 0.05. What is the p-value?
(f) Construct descriptive statistics for blood glucose level before the drug was administered and comment.
(g) What is the correlation between blood glucose levels before and after administration of the drug? Test whether the correlation differs from zero. Use α = 0.05.
(h) Construct a 98% confidence interval for the variance of systolic blood pressure after administration of the drug.
