PCAT Statistics 4

Question 1

A drug study uses a two-tailed t-test with 20 degrees of freedom at α = 0.05. The critical t-value is approximately 2.086. If the calculated t = 2.5, what is the conclusion?

Accepted Answer

Reject the null hypothesis

Answer

Since |t| = 2.5 > 2.086 (critical value), the null hypothesis is rejected.

Question 2

What is the probability of rolling a sum of 7 with two fair six-sided dice?

Accepted Answer

1/6

Answer

There are 6 favorable outcomes (1+6, 2+5, 3+4, 4+3, 5+2, 6+1) out of 36 total, so P = 6/36 = 1/6.

Question 3

A researcher calculates a 90% confidence interval instead of a 95% CI using the same data. How does the width change?

Accepted Answer

The interval becomes narrower

Answer

Lower confidence levels correspond to smaller critical values, producing narrower confidence intervals.

Question 4

Which statistical test compares proportions between two independent groups?

Accepted Answer

Chi-square test of independence

Answer

The chi-square test of independence compares categorical proportions between two or more independent groups.

Question 5

In hypothesis testing, what does increasing the sample size primarily accomplish?

Accepted Answer

Increases statistical power

Answer

Larger samples reduce standard error, making it easier to detect true effects and increasing statistical power.

PCAT - Pharmacy College Admission Test Practice Test

PCAT - Pharmacy College Admission Test Practice Test

PCAT Statistics 4