Two investigators are interested in studying the health of men 18-24 years old in Baltimore City. Investigator A plans to take a random sample of 100 men age 18-24 from Baltimore City. Investigator B will take a random sample of 1,000 such men. Both investigators will measure the waist size of men in their samples.

For which sample size (n=100 or n=1,000) will sample mean estimates tend to be closer on average to the true population mean?