A researcher interested in relationships developed a questionnaire that measures the degree of affection adult men feel for their fathers. She has found that for the general population the distribution is skewed to the right, the mean degree of affection is 60, and the standard deviation is 16. The researcher now is wondering if men who themselves have just become new fathers will score higher on the scale than men in general. She samples a group of 100 new fathers and finds that their mean is 64.5.

Question

A researcher interested in relationships developed a questionnaire that measures the degree of affection adult men feel for their fathers. She has found that for the general population the distribution is skewed to the right, the mean degree of affection is 60, and the standard deviation is 16. The researcher now is wondering if men who themselves have just become new fathers will score higher on the scale than men in general. She samples a group of 100 new fathers and finds that their mean is 64.5.
What is the variance on this questionnaire in the general population?

Sean · Answer

This sounds like a trick question. If the standard deviation of the answer from the general population is 16, then the variance is σ², which is 256.

jean · Answer

For a population with a standard deviation of ƒã = 8, a score of X = 44 corresponds to z = -0.50. What is the population mean?