1. The length of a species of fish is to be represented as a function of the age and water temperature. The fish are kept in tanks at 25, 27, 29 and 31 degrees Celsius. After birth, a test specimen is chosen at random every 14 days and its length measured.

data=read.csv("http://bsmith.mathstat.dal.ca/stat3340/Data/fish.csv",header=T) age=data[,1] temp=data[,2] length=data[,3] N=dim(data)[1] y=length X=cbind(rep(1,N),age,temp) X[1:3,] ## age temp ## [1,] 1 14 25 ## [2,] 1 28 25 ## [3,] 1 41 25 

Fit the modely=0+1x1+2x2+

y=0+1x1+2x2+

using matrix commands in R. Calculate and display the 3x3 matrixXX

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