Question

Problem 2. (15pts) A hospital performs a study to investigate the effect of a new medicine on the number of days it takes patients to recover from surgery. Twelve patients are divided at random into two groups of six each. The first group is treated as usual, while the second group is treated with the new medicine. For the first group, the recovery times had a mean of 14.8 days and a variance of 3.9; for the second group, the recovery times had a mean of 13.9 days and a variance of 4.3. Assume that the populations of recovery times under both treatments have normal distributions with equal standard deviations and that the two samples are independent. (1) Set up the null and alternative hypotheses to test if the new medicine reduced the recovery time after surgery. (2) The value of the test statistic is b) .77 a).98 c)-2.06 d) 2.72 e) 1.73

Is the correct answer to #2 B?

Answer 1

The statistical software output for this problem is:

Two sample T summary hypothesis test: : Mean of Population 1 μ2 : Mean of Population 2 μι-u2 : Difference between two means with pooled variances) Hypothesis test results: Difference Sample Diff Std. Err. DF T-Stat P-value 0.9 1.1690452 10 0.76985903 0.2296

Hence,

1) Hypotheses: Option D is correct.

2) Test statistic = 0.77

Option B is correct.