A health psychologist knows the smoking population at the hospital where she works smokes an average of 18 cigarettes per day with a standard deviation of 7. She plans to conduct a program to reduce smoking. If she has 25 persons in her program, what is the power to detect a real effect of the program such that cigarette consumption is reduced, on the average, by 5 cigarettes? Assume population normality and use a = 0.05 1 tail .
A) Insufficient information
B) 0.9732
C) 0.9463
D) 0.8925

Question

Quizplus · Accepted Answer

To calculate the power of the test, we use the formula for the power of a one-sample t-test, considering the effect size, sample size, significance level, and the standard deviation. Given the reduction in cigarette consumption (effect size = 5), the standard deviation (σ = 7), the sample size (n = 25), and the significance level (α = 0.05 for a one-tailed test), we can calculate the test's power. The correct power value, based on these inputs and using statistical software or power tables, is 0.9732. This indicates a high likelihood of detecting a true effect of the program if it exists.

A Health Psychologist Knows the Smoking Population at the Hospital