"Famous Five" Example... something to riff on for later

famous-five-example.R

set.seed(8675309)

tibble(age = round(runif(25,18,80)),
       e = rnorm(25,0,5),
       approval = round(1.25*age + e)) -> Dat

Dat %>%
  ggplot(.,aes(age, approval)) +
  geom_point()

summary(M1 <- lm(approval ~ age, data=Dat))

Dat %>%
  summarize(sum_approval = sum(approval),
            sum_approval2 = sum(approval^2),
            sum_age = sum(age),
            sum_age2 = sum(age^2),
            sum_prod = sum(age*approval)) %>%
  gather()


XY <- cbind(1,Dat$age,
            Dat$approval)

t(XY) %*% XY