1. Which of the following is NOT an assumption of the multiple regression model?a) The value of y, for each value of xik, is: yi = 1 + 2x i2 + … + Kx iK + ei b) The value of y, for each value of x, is: y = 1 + 2x + e c) Cov(ei , ej) = 0 , i ≠ j d) E(e)= 2. You have estimated a model of two variables related such that ŷ = 16.8 20 x If x increases by 1 unit, what is the expected change in y? ‐3. A model estimated using a dataset with 500 observations generates the following results.ŷ = 3.204 + 0.76 x2 (se) (0.709) (0.44) What are the endpoints for the 99% confidence interval for 2? Percentiles of the tdistribution: t(.95,df) =1.645, t(.975,df) =1.96, t(.99,df) =2.326, t(.995,df) =2.576 ‐‐4. How should bk in the general multiple regression model be interpreted?