2. A study was conducted to assess whether added calcium in the diet significantly reduces blood pressure. Thirty-two men with hight blood pressure were willing to serve as subjects. Each subject took either a white tablet that contains calcium or a dummy pill that looks and tastes like the calcium pill but has no active ingredient. The men did not know which pill they took but the researchers knew. The diastolic blood pressure of each subject was measured after taking the tablet daily for three months. The diastolic blood pressure reductions (in millimeters of mercury) for the group of men who took the calcium pill are given below.

3.1	2.7	3.5	3.3	3.2	2.2	2.6	2.4
0.4	2.6	2.1	2.2	2.8	1.9	4.0	1.4

(a) This study is (select your answer)

1. an observational study.
2. a single-blinded experiment.
3. an experiment, but not a single-blinded experiment.
4. a confounding study.

(b) The variable "blood-pressure reductions" is (select all correct answers)

1. the explanatory variable.
2. a discrete variable.
3. a confounding variable.
4. a quantitative variable.
5. the response variable.
6. a continuous variable.
7. a qualitative variable.

(c) To assess overall compliance, the number of the tablets taken over the 30-day study was recorded for each subject. This variable "total number of tablets taken" is (select all correct answers)

1. the explanatory variable.
2. a discrete variable.
3. a confounding variable.
4. a quantitative variable.
5. the response variable.
6. a continuous variable.
7. a qualitative variable.

(d) Give the sample mean and sample standard deviation for the blood-pressure-reduction rate.

(e) Use the following steps to determine how many men had their blood pressure reduced within one standard deviation of the mean.

Step 1: Compute the interval [xs,x+s][xs,x+s].

Step 2: Count the number of observations in the interval.

(f) Identify what each of the five-number summary is and give its value for the blood-pressure data.

(g) Draw a modified box plot for the blood-pressure-reductions data. Be sure to include the values and labels for the five-number-summary.

(h) Determine whether there are any outliers, using the 1.5 x IQR rule (hint - the modified box and whisker plot on the TI shows the outliers based on this rule).