On a scale drawing of a​ fence, 1875 inches represent 12 feet. Estimate the actual length of a second fence that is 3.8 inches in the drawing. Then find the exact length

Question

I can not find out how to get this answer.

Answer 1

12/1875 = x/3.8, solve for x

the ratios of feet to inches is the same

cross multiply

1875x = 12(3.8) = 45.6

x = 45.6/1875 = 0.0243 feet = 12(0.0243) inches = 0.29184 inches

the ratio of 12/1875 is feet/inches, change the inches to feet, with 1875 in.= 1875/12 feet = 156 1/4 feet

then the ratio is 12/156 1/4 feet, or a little larger than 1:12 ratio

If the scale drawing has 3.8 inches, then the actual size is near 1/12 that amount or 3.8/12 inches = close to 0.3 inches. Actual size is about 3/10 of an inch