Consider data x1, . . , xn and y1, . . , yn. say that we have the regression model yi = θxi + εi , where the εis are independent and identically distributed normal random variables with mean 0 and variance σ 2 . assume that x1, . . , xn are not random. a) find the maximum likelihood estimate for θ. b) what is the mean squared error for your estimate ˆθ? it will depend on θ and σ 2 as well as x1, . . , xn.