To determine the relationship between miles and kilometers, if we use the conversion 39.37 inches= 1 meter, we find that 1 kilometer is approximately equal to 0.62 mile. What if we use the conversion 2.54 centimeters = 1 inch? How far apart are the answers (1 kilometer = x miles) obtained by using the different conversions?

Question

To determine the relationship between miles and kilometers, if we use the conversion 39.37 inches= 1 meter, we find that 1 kilometer is approximately equal to 0.62 mile.  What if we use the conversion 2.54 centimeters = 1 inch?  How far apart are the answers (1 kilometer = x miles) obtained by using the different conversions?

Reiny · Answer

2.54 cm = 1 inch (official definition of inch since 1959)
1 cm = 1/2.54 inches
1 m = 100/2.54 inches

1 km = 1000(100/2.54) inches
= 100000/(2.54*12*5280) miles
= .62137 miles

which is the same as your other definition correct to 2 decimals.