Sale of spinach that is contaminated with e coli can cause food poisoning among consumers. A food inspector takes an SRS of 400 bags from all the bags of spinach shipped in one day. The laboratory reports that 19 of these bags had e coli contamination. Unknown to the producer, 1 percent of all bags shipped had e coli.
If the producer took an SRS of 200 bags instead of 400, the new margin of error would be:
A) the same as before because the population of bags is the same.
B) smaller than before because the sample is smaller.
C) larger than before because the sample is smaller.
D) random in size and could be either larger or smaller than before.
E) impossible to determine because the size of the sample doesn't control the margin of error.

Question

Quizplus · Accepted Answer

The margin of error decreases with larger samples and increases with smaller samples. Therefore, if the producer took an SRS of 200 bags instead of 400, the margin of error would be larger than before because the sample size is smaller.

Sale of Spinach That Is Contaminated with E Coli Can