(Bonus 5 points) A researcher has developed a new drug designed to reduce blood pressure. In an experiment, 21 subjects were assigned randomly to the treatment group and received the new experimental drug. The other 23 subjects were assigned to the control group and received a standard, well-known treatment. After a suitable period, the reduction in blood pressure for each subject was recorded. The test results are shown below.
Sample Size Mean Variance
Treatment group (new drug) 21 23.48 64.3
Control group (old drug) 23 18.52 49.8
Test to see if the new drug, on average, had a greater reduction in blood pressure than the old drug. Assume approximately normal populations. Do not assume the population variances are equal. Use a significance level of 0.07.
(a) State your hypotheses.
(b) Calculate your test statistic (round z-values to 2 decimals, and t-values to 3 decimals).
(c) State the critical region or calculate the p-value.
(d) State your decision.
(e) State your conclusion.