Question

In the HANES5 sample, the average height of the boys was 137 cm at age 9 and 151 cm at age 11. At age 11, the average height of all the children was 151 cm.

a. On the average, are boys taller than girls at age 11?
b. Guess the average height of the 10-year-old boys.

Answer 1

a) Average age of girls is also 151.

b)
`h_(10)=144cm`

Explanation:

From the question we are told that:

Average height of the boys at age
`h_9= 137 cm`

Average height of the boys at age
`h_11= 151 cm`

a)

Since

The average height of all the children was 151 cm.

This implies that The average height of all children is 151

Therefore

Average age of girls is also 151.

b)

Assuming all factors being equal

Height of 10 year old boy

`h_(10)=(h_9+h_11)/(2)`

`h_(10)=(137+151)/(2)`

`h_(10)=144cm`

Therefore my Guess is

`h_(10)=144cm`