Is the regression equation a good model based on R²? (see info/equation below)

QAW = -150,000 - 2400 PAW + 1520PGearS + 1200 PPebble - 1200 PiPhone6 + 44 A

QAW is the quantity demanded of the Apple Watch per week.

PAW is the price of the Apple Watch (dollars per unit).

PGearS is the price of the Samsung Gear S watch (dollars per unit).

PPebble is the price of the Pebble Steel (dollars per unit).

PiPhone6 is the price of the mid-range iPhone 6 smartphone (dollars per unit).

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

dollars per quarter).

As the team prepared for launch, they contemplated a scenario with the following variable values: PAW =$349, PGearS =$380, PPebble =$220, PiPhone6 =$299, A=$15,500. Regression analysis results showed the coefficient of determination to be 0.7581 and the standard error of the estimate to be 30,000.