The sample size needed to estimate a population mean within 1.5 units with a 95% confidence when the population standard deviation equals 10 is:

A) 121
B) 13
C) 171
D) 54
E) 88

Population Mean

The average value of a characteristic of the entire population.

Population Standard Deviation

The square root of the variance in a population, describing how data points in the entire population deviate from the population mean.

Sample Size

The number of observations or items included in a sample, which represents a portion of the larger population.