Problem 4. Cholesterol levels (12 marks) A pharmaceutical company introduced a new drug that would reduce cholesterol levels. A researcher selected 10 cholesterol patients and tested them for their cholesterol level. The subjects were then placed on the new drug for a period of 6 months, and the cholesterol level reading was taken again. Both the results are given below. Assume the samples are random and dependent, and the populations are normally distributed. Use 0.01 level of significance and test whether there is evidence of reduced cholesterol level. Subject A B C D E F G H Before 196 224 201 196 176 259 265 193 240 268 After 181 219 209 176 170 229 255 190 240 250 a. Is the sampling dependent or independent in this study? Justify your answer. [2 marks] e. Use the critical value approach, test whether there is evidence of reduced cholesterol level. Include all key steps of the test. [10 marks]