

In [ ]:

    
library(ISLR)
summary(Carseats)



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lm.fit <- lm(Sales ~ Price + Urban + US, data = Carseats)
summary(lm.fit)

b)

Price: negative relation UrbanYes: No significant relation USYes: positive relation

c)

$$Sales = -0.054459 * \text{Price} + -0.021916 * \text{UrbanYes} + 1.200573 * \text{USYes}$$



In [ ]:

    
lm.fit2 <- lm(Sales ~ Price + US, data = Carseats)
summary(lm.fit2)



In [ ]:

    
confint(lm.fit2)



In [ ]:

    
plot(predict(lm.fit2), rstudent(lm.fit2))