################## interpret the results

############## add regression line

library(ggplot2)

ggplot(Orange, aes(x=age, y=circumference)) + 
  geom_point(color='#2980B9', size = 4) + 
  geom_smooth(method=lm, color='#2C3E50')

fit=lm(circumference~age,data=Orange)

summary(fit)


p=
  ggplot(Orange, aes(x=age, y=circumference)) + 
  geom_point(color='#2980B9', size = 4) + 
  geom_smooth(method=lm, color='#2C3E50')

p1 <- p + ggtitle("OLS regression line")
p1

head(Orange)

#predict the circumfrence of a tree aged 1500
age=1500

circ=0.106*age
circ