Question 2 Statins are pharmaceuticals that lower LDL (low density lipoprotein)-cholesterol levels by slowing down the production of cholesterol by the liver. A groups of patients who suffered from high LDL-cholesterol

levels and high total cholesterol levels, each group starting with approximately the same mean LDL- cholesterol level (around 5.30 mmoldm³) and same mean total cholesterol level (around 6.80 mmoldm-³). A placebo was given daily to one set of patients (of group size=24) and the blood plasma LDL-cholesterol levels and total cholesterol levels were recorded after 70 days of treatment. The second group of patients (of group size = 22) were treated daily with the pharmaceutical and the LDL-cholesterol levels and total cholesterol levels in their blood plasma were measured after the same period of time. The results are shown below in Table 2: TABLE 2: EFFECT OF A PHARMACEUTICAL ON THE TOTAL BLOOD CHOLESTEROL LEVELS IN HUMANS. Total blood plasma cholesterol concentration (mmoldm³) Placebo-treated Pharmaceutical- Patients (n=24) treated Patients (n=22) 7.90 6.59 6.44 6.27 7.66 7.33 6.25 6.88 7.58 7.21 6.48 6.93 6.41 6.41 6.82 6.36 6.26 6.19 6.33 6.74 6.39 6.72 8.03 7.27 5.53 4.75 4.51 4.59 5.15 6.13 4.38 5.44 5.92 6.12 5.31 5.67 4.56 4.67 5.17 4.45 4.78 4.56 4.96 5.11 4.92 5.31 Blood plasma LDL-cholesterol concentration (mmoldm3) Placebo- treated Pharmaceutical- treated patients Patients (n=22) (n=24) 6.22 4.11 4.10 5.55 5.67 6.11 4.56 5.17 6.01 5.97 5.12 5.48 4.96 4.77 4.98 5.25 5.66 5.83 4.64 4.49 4.64 6.13 6.35 6.09 4.66 2.99 3.13 4.44 4.33 7.35 2.97 3.25 4.68 3.56 4.72 4.91 3.62 3.75 4.78 2.67 3.03 3.11 3.02 2.90 3.35 4.78/n(a) You are required to use Microsoft Excel to perform relevant calculations to compare these two sets of data. You are also asked to determine whether the pharmaceutical significantly reduces the total blood cholesterol levels and the LDL-cholesterol levels in humans. (1) Transfer the data to a spreadsheet and use appropriate formulae to determine the measures of location and the measures of spread (dispersion) for the total cholesterol levels in the placebo- treated and pharmaceutical-treated patients. (ii) Draw box plots (box and whisker plots) for both sets of data in (i). Label both box plots and comment on the skewness of the data in both plots. (iii) Carry out an appropriate statistical test to determine whether the two sets of data in (1) are statistically different. Justify your use of the statistical test. (iv) Repeat steps (i) to (iii) for the LDL-cholesterol levels in the placebo-treated and pharmaceutical-treated patients. (v) When you have completed your Excel spreadsheet, transfer your tables and box plots to a word document for both sets of data (total cholesterol and LDL-cholesterol). (vi) What is a double-blind clinical trial and what is the purpose of the giving a group of patients a placebo? (b) You should now write a detailed discussion of the results in your word document. This discussion should involve: 1. Comments on the quality of the data. 2. Justification of your conclusion as to whether the pharmaceutical has significantly lowered total blood cholesterol levels and the LDL-cholesterol levels in humans. [Total 35 marks]