Which random variable is a better estimation of the number of gallons of milk a family buys per week in the United States?

Question

A random variable Y represents the number of gallons of milk a family buys in a week in Paris, TX. Another random variable Z represents the number of gallons of milk a family buys in a week in all of Texas. Which random variable is a better estimation of the number of gallons of milk a family buys per week in the United States? Why?

Answer 1

Z is a better estimate because the sample size (Texas) is larger than Y (Paris) and will provide an estimate with less variation.