# Can someone help explain how to do #22? Thanks!

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A scale model has the dimensions of 2.5in wide and 4.5in tall. The actual figure is 60ft wide and we are asked to find the actual height.

There are two good approaches:

(1) Since the figures are similar their sides are proportional. So `w_1/h_1=w_2/h_2` where w is the width of the figure and h is the height.

`2.5/4.5=60/h ==> 2.5h=270 ==> h=108`

**Thus the height is 108 ft.**

(2) Alternatively, we can find the scale factor. If 2.5in represents 60ft, then we divide both numbers by 2.5 to get 1in represents 24ft. Since the scale model is 4.5in tall, we take (4.5)(24)=108.

**Again we find the actual height to be 108 feet.**