Predicting children's height

Using Galton's data to predict children's height using parents height

Sasa Pavkovic

The data are recorded in class intervals of width 1.0 in. He used non-integer values for the center of each class interval because of the strong bias toward integral inches.
All of the heights of female children were multiplied by 1.08 before tablulation to compensate for sex differences.

In the data analysis a simple linear model is built.

Using this model we are trying to predict the height of a child in inches.

lm1 <- lm(child~parent,data=galton)
lm1

## 
## Call:
## lm(formula = child ~ parent, data = galton)
## 
## Coefficients:
## (Intercept)       parent  
##      23.942        0.646

Prediction is done by using the coefficients of the linear model based on the mid-parent height of parents.

Here is an example with mid-parent height of 75 inches.

newdata <- c(75)
prediction <- lm1$coef[1] + lm1$coef[2] * newdata
prediction

## (Intercept) 
##       72.41

Thank you for participating!

Additional infromation can be found on these links: