Question

The ages of a group of 154 randomly selected adult females have a standard deviation of 17.6 years. Assume that the ages of female statistics students have less variation than ages of females in the general​ population, so let σ equals=17.6 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 98​% confidence 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?

Answer 1

Given,

σ = 17.6

E = 0.5

For 98% confidence, z = 2.326

Hence,

Sample size required

n = 6704

Yes, it is reasonable to assume because female students are typically younger than entire population.