Question 72450
<pre><font size = 5><b>Business and finance. The revenue for a sandwich 
shop is directly proportional to its advertising 
budget. When the owner spent $2000 a month on 
advertising, the revenue was $120,000. If the 
revenue is now $180,000, how much is the owner 
spending on advertising.

>>...The revenue for a sandwich shop is directly 
proportional to its advertising budget...<<

The formula is 

          R = kA

>>...When the owner spent $2000 a month on 
advertising, the revenue was $120,000...<<

Plug that in the formula:

      120000 = k(2000)

Solve that for k

      120000 = 2000k

Divide both sides by 2000

          60 = k

Now plug 60 for k in the formula:

          R = kA

          R = 60A

Now plug 180000 for R:

     180000 = 60A

Solve for A. Divide both sides by 60

       3000 = A

So the owner is now spending $3000 per month 
on advertising.

Edwin</pre>