To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at General Electric selects every 20th refrigerator that comes off the assembly line starting with the sixth until she obtains a sample of 130 refrigerators. What type of sampling is used? (a) Simple random (b) Systematic (c) Cluster (d)Convenience (e) Stratified

A systematic random sampling is kind of sampling method in which samples are chosen from a larger population based on a random beginning point that has a definite and periodic interval.

Given statement : To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at General Electric selects every 20th refrigerator that comes off the assembly line starting with the sixth until she obtains a sample of 130 refrigerators.

Periodic interval : Every 20th

Beginning point : 6th

Sample size : 130

Hence, this type of sampling is a systematic random sampling.