Answer:
Step-by-step explanation:
Given : To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at Microsoft selects every 16th software CD that comes off the assembly line starting with the eighth until she obtains a sample of 140 software.
Since the control manager is maintain an specific periodic interval to draw sample.
Therefore , this sampling method is "Systematic ".
- Systematic random sampling is a particular type of random sampling technique in which samples are chosen from the entire population by starting with a random starting point but with a fixed periodic interval.
Hence, the correct answer is A. Systematic.
Further more :
- In Cluster researcher divides the population into clusters and then select random cluster.
- In simple random ,he randomly pick participants from population.
- In Convenience ,he draw sample as per his convenience.
- In stratified , he divides the population into strata, then he randomly pick participants from each strata.
