Question

The ages of a group of 154 randomly selected adult females have a standard deviation of 17.9 years. Assume that the ages of female statistics students have less variation than ages of females in the general​ population, so let sigmaequals17.9 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​% 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 nothing. ​(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? A. ​Yes, because statistics students are typically older than people in the general population. B. ​No, because there is no age difference between the population of statistics students and the general population. C. ​Yes, because statistics students are typically younger than people in the general population. D. ​No, because statistics students are typically older than people in the general population.

Answer 1

for 95 % CI value of z=	1.960
standard deviation σ=	17.90
margin of error E =	0.5
required sample size n=(zσ/E)2                                         =	4924.0

C. ​Yes, because statistics students are typically younger than people in the general population