Author Question: Based on 12,500 responses from 29,000 questionnaires sent to all its members, a major medical ... (Read 26 times)

Chloeellawright · **on:** Jul 25, 2018

Based on 12,500 responses from 29,000 questionnaires sent to all its members, a major medical association estimated that the annual salary of its members was 92,000 per year. What sampling technique was used?

A) stratified
B) systematic
C) simple random
D) cluster
E) convenience

Question 2

The lifetimes of lightbulbs of a particular type are normally distributed with a mean of 250 hours and a standard deviation of 6 hours. What percentage of the bulbs have lifetimes that lie within 2 standard deviations to either side of the mean?

A) 99.74 B) 68.26 C) 95.44 D) 97.72