he mean of a sample is an unbiased estimate of the population mean. However, the population variance tends to be ( greater / less ) than the variance of a sample drawn from that population, because sample variability underestimates population variability. (½) For this reason, the variance formula is adjusted when the sample variance is used. This factor changes the denominator of the variance formula to n - 1, which is also referred to as:
a) Bessel's Correction
b) Fisher's Ratio
c) Neyman's Adjustment
d) Pearson's Scale