#### Answer

18,000 dollars

#### Work Step by Step

We are given that the total revenue (in dollars) for MCD, Inc., Manufacturing Company to sell x blank CDs per weeks is given by $R(x)=.9x$. To find the total revenue from selling 20,000 CDs per week, we can plug in 20,000 to the given function.
$R(20000)=.9(20000)=18000$