Hello, Sprinkledozer!

A telephone company estimates that the number N of phone calls per day

between two cities of population and that are miles apart is given by:

. .

115. Estimate the population of a city given that

. . . . . the population of a second city is: ,

. . . . . the number of phone calls per day is: ,

. . . . . and the distance between the cities is: miles.

. . . Round to the nearest thousand.

First, solve for

We have: .

Multiply by

Divide by

Substitute: .

Therefore: .