The mathematical expresion of the model is given by the equation,
Y = \(\beta_0 + \beta_1 X_1 + \epsilon\)
where \(X_1\) = father’s height and \(\epsilon\) = random error
Galtons <- read.csv("/cloud/project/Galtons.csv")
reg <- lm(Height~Father,data=Galtons)
summary(reg)
##
## Call:
## lm(formula = Height ~ Father, data = Galtons)
##
## Residuals:
## Min 1Q Median 3Q Max
## -10.2683 -2.6689 -0.2092 2.6342 11.9329
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 39.11039 3.22706 12.120 <2e-16 ***
## Father 0.39938 0.04658 8.574 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 3.446 on 896 degrees of freedom
## Multiple R-squared: 0.07582, Adjusted R-squared: 0.07479
## F-statistic: 73.51 on 1 and 896 DF, p-value: < 2.2e-16
Using the model fit, I think the model is useful, as the overall model is significant, F(2,895) = 54.69, p < .001
My height = 70 inches Father’s height = 73 inches Mother’s height = 67 inches Parent’s Height = (73 + 67*1.08)/2 = 72.68 inches
From the model, My height = 39.11 + 0.40*72.68 = 68.18 inches
The model underestimates my height by 1.82 inches.