please help me with this question to understand

The ages of a group of 128 randomly selected adult females have a standard deviation of 17.3 years. Assume that the ages of female statistics students have less variation than ages of females in the general population, so let 6 = 17.3 years for the sample size calculation. How many female statistics student ages must be obtained in order to estimate the mean age of all female statistics students? Assume that we want 95% condence that the sample mean is within one-half year of the population mean. Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? The required sample size is D. (Round up to the nearest whole number as needed.) Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? 0 A. Yes, because statistics students are typically older than people in the general population. 0 B. Yes, because statistics students are typically younger than people in the general population. 0 C. No, because there is no age difference between the population of statistics students and the general population. 0 D. No, because statistics students are typically older than people in the general population