Question

According to the National Health Statistics report, the mean height of all adult (age 18 years and older) males in the United States in 69.4 inches. A random sample of 300 men aged 60 – 69 years old has a mean height of 69.0 inches, with a standard deviation of 2.65 inches. At α = 0.10, can we conclude that the population of older (aged 60 – 69 years old) men are shorter than the population of all men in the USA? (Be sure your answer is in the appropriate format.)

Answer 1

Since sample size is large so we can use z test instead of t test even though population standard deviation is unknown.

Conclusion: There is evidence to conclude that the population of older (aged 60 – 69 years old) men are shorter than the population of all men in the USA.