7.5% of the box office reciepts on a friday night are $270. what are the total box office reciepts

Hello there! To solve for the total box office receipts, we can write and solve a proportion. Set it up like this:

270/x = 7.5/100

We do that, because we are looking for the total and 270 is the part of the whole. 270 makes up 7.5% of the box office receipts. 
Now, we cross multiply. 270 * 100 is 27,000. 7.5 * x is 7.5x. Divideeach side by 7.5 to isolate the "x". 7.5x/7.5 cancels out the "x". 27,000/7.5 is 3,600. There. x = 3,600. The total box office receipts are $3,600.