with info below

QAW = -150,000 - 2400PAW + 1520 PG + 1200Pp - 1200P IPHONE + 44A

QAW is the quantity of Apple Watches sold per week

PAW is the price of an Apple Watch in dollars per unit;

PG is the price of Samsung Gear smartwatch in dollars per unit;

Pp is the price of the Pebble Steel smartwatch in dollars per unit;

P IPHONE is the price of an iPhone;

A is the quarterly advertising budget for Apple Watch in thousands of dollars

1. Apple sold 177,200 watches per week.

PAW =349 Pg = 380, Pp= 220 PiPhone= $299 A = 15,000

QAW =-$150,000 - 2400(349) + 1520(380)+1200( 220) - 1200 (299) + 44(15,500)

QAW=$177,200

1. The price elasticity of demand for Apple Watch is -4.726

-2400(349)= -4.726

177,200

what is cross price elasticity for apple watch and why? explain