Answer: 112 km
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Work Shown:
(5 miles)/(8 km) = (70 miles)/(x km)
5/8 = 70/x
5*x = 8*70 ... cross multiply
5x = 560
x = 560/5 .... divide both sides by 5
x = 112
According to the given estimation, 70 miles converts to 112 km.
The more accurate conversion is approximately 70 miles = 112.65408 km, so this estimation isn't too far off.