Question

John’s parents recorded his height at various ages between 36 and 66 months.Below is a record of the results:Age(A,months) 36 48 54 60 66Height(H, inches) 34 38 41 43 45a. Determine the equation of the least-squares regression line of John’s height on age.b. John’s parents decide to use the least-squares regression line of John’s height on age to predict his height at age 21 years (252 months). What conclusion can we draw?

Answer 1

Explanation:

Given that John’s parents recorded his height at various ages between 36 and 66 months.

Below is a record of the results:

Age A Height H

36 34

48 38

54 41

60 43

66 45

Slope 0.373873874

Intercept 20.45945946

We find the regression equation has positive slope and for a new born child height is intercept

`H = 0.3739A+20.4595`

is the relation between height and age.

But this is valid only for nearer values of x and y.

When we find 252 months this is very far from the age we have considered and hence will not be reliable

H(252) =
`0.3739(252)+20.4595\\=114.6823`

as per regression equation line.