The following regression model has been proposed to predict sales at a computer store:

y_hat = 50 – 3x1 + 20x2 + 10x3

where

x1 = competitor's previous day's sales (in $1000s)

x2 = population within 1 mile (in 1000s)

x3 = ​1 if any radio advertising was used and 0 otherwise.

y_hat= sales (in $1000s)


Predict sales (in dollars) for a store with the competitor's previous day's sale of $5000, a population of 20,000 within 1 mile, and nine radio advertisements.