Psychological Statistics:

t-test for two independent samples (Using PHStat)

Problem: A cardiologist wishes to determine which of the two drugs A or B is more effective in lowering diastolic blood pressure (BP). In a group of 50 patients, he administered Drug A and found out that mean diastolic BP was 85 with a standard deviation of 4.7 while the 60 patients who took Drug B have a mean diastolic P of 79 with a standard deviation of 6.1. Would you say that the diastolic BP of those taking Drug A increases those of Drug B by more than 8 mmHg? Use a = 0.01 and assume the populations to be approximately normally distributed.

By answering the following questions:

Step 1: Problem Statement

Step 2: State the hypothesis and identify the claim

e.g.

H0:

Ha:

Variables:

What is Dependent?

What is Independent?

Step 3: Choice of test statistic and level of significance

Step 4: Computation (using PHStat)

Step 5: Decision rule and finding

e.g. (Decision rule: Reject H0 if level of significance (a) > p - value )

Finding: a (0.0500) > p - value (0.0000)

Step 6: Decision

e.g.

Reject the null hypothesis

type 1 error

Step 7: Interpretation and Analysis

Step 8: Implications

Step 9: Conclusion