14. Suppose that manufacturing cost of a precision electronic calculator is approximated by M( x y) = 40 x + 30 9 - 19xy+30 Where is cost of electronic chip and y is cost of labor. Find the following: 14 (aM(3,6) 14 ( 6 ) OM ( 6 1 7 ) dy 15. A car dealership estimates that the total weekly sales of its most popular model is a function of the car list price, p, and the interest rate in percent, i, offered by a manufacturer. The approximate weekly sales are given by f [ Pic ) = 130 p - 2pi-. 0172 15(a). Find the weekly sales if the average list price $9400 and manufacturer is offering 8% interest rate: 15(b). What Find and interpret f.( P, ( ) : 15(c). What would be the effect on weekly sales if the price stays 9400 and the interest rate is changed from 16. Let f ( x, y) = +xy - 8x +q y 8% to 9%: Find all points where the function have a relative extrema. Identify any saddle point. 16(a). Any minimum point: 16(b). Any maximum point: 16(c) Any saddle point: 17. Suppose the labor cost (in dollars) for manufacturing a precision camera can be approximated by L ( x , y ) = 3 x + 9 - 2 x-zy-zxy+75 where x is the number of hours required by a skilled craftsperson and y number of hours required by a semiskilled person. Find the values of x and y that minimize the labor cost. 17. Minimum labor cost