d) Using the Calcium Database (homework 1 data). The data were collected to investigate whether increasing calcium intake reduces blood pressure. Twenty-one people participated in this experiment, where 10 of them took a calcium supplement for 12 weeks, while the remaining 11 received a placebo. The blood pressure of each subject was measured before and after the 12- week period. What kind of variables are Begin and End and what kind of scale are they following? ( Plot the frequency histogram of the variables Begin and End. Compare the two histograms in terms of their central tendency and the form of their histogram not only in statistical terms but also the applied meaning of the differences in the shapes. Plot the box plot of both variables, Begin and End. Highlight where the Quartile 1 is and specify if there are any outliers. Obtain the mean, median, standard deviation of each variable and each variable by treatment. How do they match with your explanation in c)? Calcium 107 100 7 Calcium 1 10 1 14 -4 Calcium 1 23 1 05 1 8 Calcium 129 1 12 17 Calcium 1 12 1 15 -3 Calcium 1 1 1 1 16 -5 Calcium 1 07 1 06 1 Calcium 1 12 1 02 1 0 Calcium 1 36 1 25 1 1 Calcium 1 02 1 04 -2 Placebo 1 23 1 24 -1 Placebo 109 97 12 Placebo 1 1 2 1 1 3 -1 Placebo 102 105 -3 Placebo 98 95 3 Placebo 1 1 4 1 1 9 -5 Placebo 1 1 9 1 1 4 5 Placebo 1 1 2 1 1 4 2 Placebo 1 1O 1 21 -1 1 Placebo 1 1 7 1 1 8 -1 Placebo 1 3O 1 33 -3