xmp13.09 {Devore5}R Documentation

data from Example 13.9

Description

The xmp13.09 data frame has 8 rows and 2 columns of data on cure temperature and ultimate sheer strength of rubber compounds.

Format

This data frame contains the following columns:

tempture
cure temperature (degrees Fahrenheit).
strength
ultimate sheer strength (psi)

Examples

data(xmp13.09)
plot(strength ~ tempture, data = xmp13.09)
fm1 <- lm(strength ~ tempture + I(tempture^2), data = xmp13.09)
summary(fm1)
xmp13.09$Tcentered <- scale(xmp13.09$tempture, scale = F)
fm2 <- lm(strength ~ Tcentered + I(Tcentered^2), data = xmp13.09)
summary(fm2)
## another approach using orthogonal polynomials
fm3 <- lm(strength ~ poly(tempture, 2), data = xmp13.09)
summary(fm3)