The multivariate demand function below will be needed for questions 12-18. Setting: Grapple, Inc. is a leading seller of laptop personal computers. However, they want to become a leading tablet seller, too. Your marketing department, aided by your economics staff, has estimated a function to help you in the quest for market leader in tablets. The variables are defined after the function. Q, = 10000 - 25P, +20P, +30P, -15Pdv 35P5 - 10P mm +0.054, +0.03A -25C +0.18 Qx= the number of Grapple tablet computers demanded per week. P, = the price of each new Grapple tablet (in $). Po = the price of each Hewpag tablet (in $). Pr = the price of each Ronova tablet. Pdx = the price to equip a tablet with Holographic digital video (in $, this is an upgrade option that enables three dimensional graphics on a tablet. Two dimensional graphics is standard equipment). Piso = the price of various screen sizes (in $, a 8 inch is standard, but upgrade options are 10 inch extra sharp, 12 inch, 12 inch extra sharp, Each also has a touch-screen option. The upgrades get progressively more expensive as the size and capability increases). Pinuta = the price of memory chip upgrades (in $). More 2 Gigabyte (Gb) chips can be added. Of course each added 2 Gb chip costs more. One 2 Gb chip is standard. Y = average annual disposable income of a typical tablet purchaser (in $). Ag = average age of a tablet purchaser (in years). A = average annual Grapple advertising expenditure (in $). C= number of computer systems the average tablet purchaser already owns. 12. If all variables remain unchanged except the price of Hewpag (Ph) tablets, which decreases by $50, then the demand for Grapple tablets will: 13. If all variables remain unchanged except the price of Holographic digital video (P.dx), which decreases by $50, then the demand for Grapple tablets will: 14. If all variables remain unchanged except the price of memory chips (Piwum), which decreases by $20 per chip, then the demand for Grapple tablets will: 15. You can tell by the sign preceding the price of Holographic digital video variable (P.dx) that Holographic digital video and Grapple tablets are: 12a. decrease by 1000 b. decrease by 1250 c. increase by 1000 d. increase by 1250 13a. decrease by 750 b. decrease by 1500 c. decrease by 1750 d. increase by 750 e. increase by 1500 f. increase by 1750 14a. increases by 200 b. decreases by 200 c. increases by 450 d. decreases by 450 e. increases by 700 f. decreases by 700 15a. normal goods b. substitute goods c. inferior goods d. complementary goods