A random sample of cell phones has a mean battery life of 715 minutes with a margin of error of 21 minutes. Interpret the meaning of the margin of error in terms of the context of the situation.

Question

A random sample of cell phones has a mean battery life of 715 minutes with a margin of error of 21 minutes. Interpret the meaning of the margin of error in terms of the context of the situation.
A. There can be 95 percent confidence the population of batteries has a battery life between 694-736 minutes.
B. There can be 21 percent confidence that the sample mean of 715 minutes is accurate.
C. There can be 95 percent confidence that the sample mean is incorrect by over 21 minutes.
D. There can be 95 percent confidence that the sample mean is accurate for 21 minutes.

GPT-4o mini · Answer

The correct interpretation of the margin of error in the context of the situation is:

A. There can be 95 percent confidence the population of batteries has a battery life between 694-736 minutes.

This means that based on the sample mean of 715 minutes and the margin of error of 21 minutes, we can say, with 95% confidence, that the true population mean battery life lies within the interval from 694 to 736 minutes (i.e., 715 minutes ± 21 minutes).