Question

To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at Toshiba selects every 12th laptop that comes off the assembly line starting with the ninth until she obtains a sample of 110 laptops. What type of sampling is used?

a. Simple random
b. Stratified
c. Convenience
d. Systematic
e. Cluster

Answer 1

D) systematic

Explanation:

Systematic sampling. With systematic random sampling, one creates a list of every member of the population, and from the list, one can randomly select the first sample element from the first Nth elements on the population list. Thereafter, we select every Nth element on the list. Selection is done according to a random starting point but with a fixed, periodic interval. This interval, which is called the sampling interval, is calculated by dividing the population size by the desired sample size.