This question is about statistics and is related to the dataset called "Carseats", which can be
obtained from the library called "ISLR". So you can simply use the following commands in R-
language to view the data:
install.packages("ISLR")
library(ISLR)
summary(Carseats)
We now consider the k-nearest neighbour regression using Sales as response and Price as
predictor.
(a) For k=3 state how the estimate y is defined in the regression context. How does this estimate
differ from that used in classification with k-nearest neighbours? Why should they differ?
(b) For k=3, calculate the regression estimate and error and show suitable graphics. (Hint: you
may use the code chunk below and note that the "error" is simply the "sum of squares of the
predicted residuals", PRESS.)
(c) Try writing a loop over k, using k=1,..., 21 and determine the k that results in the smallest
error. Comment.
Code Chunk for knn is the following:
Carseats.knn <- knn.reg(train = Carseats$Price, y = Carseats$Sales, k=3) Carseats.knn
Please show all your answer step by step, and show your code using R language please, thank
you..
This question is about statistics and is related to the dataset call.pdf
1. This question is about statistics and is related to the dataset called "Carseats", which can be
obtained from the library called "ISLR". So you can simply use the following commands in R-
language to view the data:
install.packages("ISLR")
library(ISLR)
summary(Carseats)
We now consider the k-nearest neighbour regression using Sales as response and Price as
predictor.
(a) For k=3 state how the estimate y is defined in the regression context. How does this estimate
differ from that used in classification with k-nearest neighbours? Why should they differ?
(b) For k=3, calculate the regression estimate and error and show suitable graphics. (Hint: you
may use the code chunk below and note that the "error" is simply the "sum of squares of the
predicted residuals", PRESS.)
(c) Try writing a loop over k, using k=1,..., 21 and determine the k that results in the smallest
error. Comment.
Code Chunk for knn is the following:
Carseats.knn <- knn.reg(train = Carseats$Price, y = Carseats$Sales, k=3) Carseats.knn
Please show all your answer step by step, and show your code using R language please, thank
you.
