The following model was fitted to a sample of 60 families in order to explain household milk consumption: yi = a+ B1X1i + B2Xzi + ui where y = milk consumption, in litres per week X1i = weekly family income, in hundreds of dollars X2i = family size. Part of the estimation results are as follows: Observations 60 Sum of Squared Residual 88.2 Total Sum of Square 162.1 Coefficients Standard Error Intercept -0.025 0.0 X1 0.052 0.023 X2 1.14 0.35a) Write down the Sample Regression Function (SRF) in an equation form and interpret each of the estimated coefficients. [4 marks] b) Determine the goodness of fit of the model estimated and explain its meaning. [3 marks] 6) Test whether family size can significantly explain the household milk consumption at the 1% level. Specify all relevant steps of the hypothesis testing procedure. [4 marks] d) Is there sufficient evidence at the 1% significance level to suggest that the higher level of household income increases milk consumption? Specify all relevant steps of the hypothesis testing procedure. [4 marks] [4+3+4+4=15marks]