this is a questiom for limear modeling. thank u so much for help.!!

:Fle 6.9] Suppose that the \"true\" model generating a set of data is Y = o: + x] + r. A researcher ts the model Y = or + 31}: 1 + 32);\"; + E, which includes the eiqznlatuaautorj.r variable X2, that is the true value of '83 is 3'. Had the researcher t the [correct] simple regression model, the variance of '51 would have been {using the simple regression formula} 1/(31) = off EX X1)? 1. ls the model Y = or. + I31 X1 + g X2 + F. wrong? In other words, is ,I'l'l for this model a biased estimator of 31%? points} 2. What is the variance of E1 in the smart model? [4 points] 3. Considering {a} and (b), what is the cost of including the irrelevant explanat-zuryr variable X2? How does this compare to the cost of failing to include a relevant tnqznlannator}r variable? (2 points} :Fle 6.9] Suppose that the \"true\" model generating a set of data is Y = o: + x] + r. A researcher ts the model Y = or + 31}: 1 + 32);\"; + E, which includes the eiqznlatuaautorj.r variable X2, that is the true value of '83 is 3'. Had the researcher t the [correct] simple regression model, the variance of '51 would have been {using the simple regression formula} 1/(31) = off EX X1)? 1. ls the model Y = or. + I31 X1 + g X2 + F. wrong? In other words, is ,I'l'l for this model a biased estimator of 31%? points} 2. What is the variance of E1 in the smart model? [4 points] 3. Considering {a} and (b), what is the cost of including the irrelevant explanat-zuryr variable X2? How does this compare to the cost of failing to include a relevant tnqznlannator}r variable? (2 points}