Let is the mean of the following numbers x,x2,.., X., (x;)=n(x) Knowing that n=11, (x)=12 and 2(x; -x) =216 find (X). i=1 i=1 b) i=1 (max. 10 points.: 3. A firm's profit is given by the function PROFIT = 1000B - 3x - 4x + 2xy - 5y + 48y, where x denotes output and y advertising expenditure. a) Find the level of output and advertising expenditure to maximize profit. Confirm that second order conditions are satisfied. Find the level of maximum profit. Find the level of x and y when the firm has constrain 2x+y=5