Question

A quality control researcher at an electronics company is testing the life of the company’s batteries in a certain camera. The researcher selects 100 batteries at random from the daily output of the batteries and finds that the life of the batteries has a mean of 342 pictures with an associated margin of error of 18 pictures. Which of the following is the most appropriate conclusion based on these data?

A. All the batteries produced by the company that day have a life between 324 and 360 pictures.
B. All the batteries ever produced by the company have a life between 324 and 360 pictures.
C. It is plausible that mean life of batteries produced by the company that day is between 324 and 360 pictures.
D. It is plausible that the mean life of all the batteries ever produced by the company is between 324 and 360 pictures.

Answer 1

C

Explanation:

The margin of error gives information about the population in general, not about a member of the population. Therefore, we can discard options A and B because we can't assume that ALL the batteries have a certain characteristic.

The quality control researcher selected batteries from the daily output, therefore, we cannot conclude anything from the batteries ever produced but the results the researcher gets can only refer to the daily output for that day. Thus, D is incorrect.

Therefore, the most appropriate conclusion would be C.