Skysong's World Toy Shop is an on-line toy store specializing in hand-made stuffed animals. Skysong's World sold 4000 Donny the Dragon stuffed toys during April and 6000 during May. Shipping costs for the two months were $13200 and $17400 respectively. Using these two months' data, the shipping cost function is best estimated as ($3.30x number of toys sold) + $3060, ($2.10 x number of toys sold) + $4800, ($2.20 x number of toys sold) + $77200 ($0.50 x number of toys sold) $11200