McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
7. Scale Drawings and Models
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Exercise 10 Page 603

Practice makes perfect
a We are given that the actual distance between the intersections of two streets with 4th Street is 0.47 miles, and we are asked to estimate the scale of the given map. Using a customary ruler, we can see that the appropriate distance on the map is 1 34 inches.

The scale of the map: 1 34in.: 0.47mi We can simplify the scale by rewriting 1 34 as a decimal. 1 34in.:0.47mi ⇓ 1.75in.:0.47mi

b In this part, we are asked to find the approximate scale factor of the map. To do this, we should express the scale only in inches. Let's evaluate how many inches we have in one mile.
1mi=1* 5280ft=1*5280*12in.=63360in. Since there are 63360 inches in one mile, we will multiply 0.47 by 63360 to convert it to inches.

0.47mi=0.47*63360in.≈29 779 With this information, we can rewrite the scale we found in the previous part using only inches. 1.75in.:0.47mi ⇓ 1.75:29 779 Finally, to determine the scale factor we will divide both sides of above scale by 1.75. 1.75:29 779 ⇓ 1:17 017 Therefore, the scale factor of this map is approximately 1:17 017. This means that the actual distance is approximately 17 017 times greater than the distance on the map.