1. In March 2005, the New England Journal of Medicine published the results of a 10-year clinical trial of low-dose aspirin therapy for the cardiovascular health of women (Time, March 21, 2005). The study was based on 40,000 healthy women, most of whom were in their 40s and 50s when the trial began. Half of these women were administered 100 mg of aspirin every other day, and the others were given a placebo. Assume that the women were assigned randomly to these two groups.

a. Is this an observational study or a designed experiment? Choose your answer; Observational study, Designed experiment Observational study.Designed experiment.

b. From the information given above, can you determine whether or not this is a double-blind study?

2. The following table lists five pairs of m and f values:

m	5	11	17	19	24
f	11	7	8	16	2Compute the value of the following. m= Enter you answer; sum of all values of m f2= Enter you answer; sum of squares of all values of f

3. The following table lists five pairs of m and f values:

m	3	8	17	18	23
f	11	6	7	15	3Compute the value of the following. mf= Enter you answer; sum of m*f m2f= Enter you answer; sum of m^2*f

4. In March 2005, The New England Journal of Medicine published the results of a 10-year clinical trial of low-dose aspirin therapy for the cardiovascular health of women (Time, March 21, 2005). The study was based on 40,000 healthy women, most of whom were in their 40s and 50s when the trial began. Half of these women were administered 100 mg of aspirin every other day, and the others were given a placebo. The study looked at the incidences of heart attacks in the two groups of women. Overall the study did not find a statistically significant difference in heart attacks between the two groups of women. However, the study noted that among women who were at least 65 years old when the study began, there was a lower incidence of heart attack for those who took aspirin than for those who took a placebo. Suppose that some medical researchers want to study this phenomenon more closely. They recruit 2000 healthy women aged 65 years and older, and randomly divide them into two groups. One group takes 100 mg of aspirin every other day, and the other group takes a placebo. The women do not know to which group they belong, but the doctors who are conducting the study have access to this information.

a. Is this an observational study or a designed experiment? Choose your answer; Observational study, Designed experiment Designed experiment.Observational study.

b. Is this a double-blind study? Choose your answer; Yes, No Yes.No.

5. Six adults spent $24, $58, $46, $72, $35, and $24 on lottery tickets last month. Let y denote last month's lottery ticket expenses for an adult. Find the following sum.

y= $ Enter you answer; sum of all values of y (y)2= $ Enter you answer; square of the sum of all y values

6. Six adults spent $29, $52, $49, $74, $36, and $17 on lottery tickets last month. Let y denote last month's lottery ticket expenses for an adult. Find the following sum.

y2= $