You have that Caroline walks 9 1/2 inches per second.
9 1/2 = (18 + 1)/2 = 19/2 = 9.5
In order to find the rate in miles per hour you use the following identities:
1 mile = 63360 inches
1 hour = 360 seconds
The previous identities are used as converstion factors. You proceed as follow:
9.5 in/s x ( 1 mi / 63360 in) x ( 360 s / 1 h) = 0.05 mi/h ≈ 0.1 mi/h
Hence, Caroline walks 0.1 mi/h
