The Centers for Disease Control and Prevention (CDC) wants to estimate the average extra hospital stay that occurs when heart surgery patients experience postoperative atrial fibrillation. They divide the United States into nine regions. In each region, hospitals are selected at random within each hospital size group (small, medium, large). In each hospital, heart surgery patients are sampled according to known percentages by age group (under 50, 50 to 64, 65 and over) and gender (male, female). This procedure combines which sampling methods?
A)Systematic, simple random, and convenience
B)Convenience, systematic, and judgment
C)Cluster, stratified, and simple random
D)Judgment, systematic, and simple random

Question

Quizplus · Accepted Answer

The procedure combines cluster sampling (dividing the United States into nine regions and selecting hospitals at random within each region), stratified sampling (sampling heart surgery patients according to known percentages by age group and gender), and simple random sampling (randomly selecting hospitals within each hospital size group).

The Centers for Disease Control and Prevention (CDC) Wants to Estimate