Question

to estimate the percentage of defects in a recent manufacturing batch, a quality - control manager selects every twentieth widget that comes off the assembly line, starting with the tenth, until he obtains a sample of sixty widgets. what type of sampling method is used? cluster systematic simple random convenience stratified

Explanation:

In systematic sampling, we select every \(k^{th}\) element from the population. Here, the quality - control manager selects every twentieth widget (so \(k = 20\)) starting with the tenth widget. This follows the pattern of systematic sampling. In cluster sampling, we divide the population into clusters and then select some of the clusters. In simple random sampling, each sample of a given size has an equal probability of being selected. In convenience sampling, we select the sample based on ease of access. In stratified sampling, we divide the population into strata and then sample from each stratum.

Answer:

systematic