Arectangular blue tile has a length of 4.25 inches and a width of 6.75 inches. a similar red tile has a length of 12.75 inches. what is the width of the red tile?

Cuz the rectangular tiles are similar, so the ratio between their lengths and widths should be the same.
The blue tile's ratio between its length and width is 4.25:6.75=17:27
The red tile's ration between its length and width is 12.75:x which is equal to 17:27, therefore the width of the red tile is 17/12.75*27=36 inches

The answer to that question your asking is 64