Question

The main trial is conducted and involves a total of 200 patients. Patients are enrolled and randomized to receive either the experimental medication or the placebo. The data shown below are data collected at the end of the study after 6 months on the assigned treatment.

	Experimental Medication (n=100)	Placebo (n=100)
Mean (s) Systolic Blood Pressure	120.2 (15.4)	131.4 (18.9)
% High Blood Pressure	14%	22%
% With Side Effects	7%	4%

1. Generate a 99.99% confidence interval for the difference in mean systolic blood pressures in the experimental group versus the placebo group.

1. True or False: The sample variances are relatively equal: (1pt)

0.5 ≤ s₁²/s₂² ≤ 2: s₁²/s₂² = ?

1. 1. True
   2. False
2. 2. Compute the Pooled Estimate of Common Standard Deviation and indicate the most appropriate answer: (2pts)
      1. Sp = 298.9891
      2. Sp = 17.2931
      3. Sp = 4.1413
      4. Since the sample variances are not relatively equal, we cannot continue the estimation of the confidence interval.
      5. Some other answer (indicate):
3. 3. Compute the confidence interval and indicate the most appropriate answer: (4pts)
      1. (-12.5207, -9.8793)
      2. (-15.9929, -6.4071)
      3. (-20.5106, -1.8894)
      4. Since the sample variances are not relatively equal, we cannot continue the estimation of the confidence interval.
      5. Some other answer (indicate):

Answer 1

Given:

a. The ratio of sample variances is:

The correct answer is:

i. True

--------------------------------------------------------------------------------------------------------------------

b. The Pooled Estimate of Common Standard Deviation is:

--------------------------------------------------------------------------------------------------------------------

c. At 99.99% confidence level, and at , the critical value of t is . The 99.99% confidence interval for the difference in mean systolic blood pressures in the experimental group versus the placebo group is:

--------------------------------------------------------------------------------------------------------------------

I used TI 84 calculator, and got same answer: