Question

The ages of a group of 142 randomly selected adult females have a standard deviation of 18.1 years. Assume that the ages of female statistics students have less variation than ages of females in the general​ population, so let sigma=18.1 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 90​% 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?
The required sample size is _____?

Answer 1

Answer:

Given that:

The ages of a group of 142 randomly selected adult females have a standard deviation of 18.1 years. Assume that the ages of female statistics students have less variation than ages of females in the general​ population, so let sigma=18.1 years for the sample size calculation

Standard deviation () = 18.1

Margion of error (E) = 0.5 yr

90% confidence interval

Critical value

Sample size

Sample size (n) = 3547

Yes.it seems reasonable to assume that the ages of female statistics student have less variation than ages of females in the general population