Question

*******Using EXCEL****

Suppose that strong claims, with weak evidence, have been made about the efficacy of an herbal treatment for attention deficit disorder (ADD). You are a research assistant for a professor who decides to empirically test the validity of these claims. You locate 10 fifthgrade students, in 10 different classrooms, who have been diagnosed with ADD. Sitting unobtrusively at the back of each classroom with stopwatch in hand, you record the number of seconds that the child with ADD is out of seat during a 20-minute period of silent reading. Each of the 10 children is then given daily doses of the herbal treatment for one month, after which you return to the classrooms to again record out-of-seat behavior during silent reading. Thus you end up with 10 pairs of observations: a pretreatment score and a posttreatment score for each student.

The data collected are given below:

Pre-score 13 10 21 13 15 7 18 13 11 10 Post-score 8 5 15 7 11 0 9 4 13 3

a. Describe the independent variable and its levels.

b. Describe the dependent variable and its scale of measurement (N.O.I.R.)

c. What does the null hypothesis predict for the problem described above. (Be sure to use the variables given in the description.)

d. Using excel Conduct the appropriate statistical test of the null hypothesis using p = .05.

e. Provide an interpretation of your statistical conclusion to part D

f. Using excel Obtain the 95% confidence interval for the sample statistic.

g. Provide an interpretation for the interval obtained in part F.

h. How does the confidence interval obtained in part F compare to your statistical conclusion in part D?

Answer 1

a) Independent variable is herbal treatment

b) Dependent variable is the number of seconds that the child with ADD is out of seat during a 20-minute period of silent reading. Scale of measurement is ratio astime can be zero too.

c)

This is a paired sample t test.

d-h)