Asalesperson ratio of successful signups to the number of people called is .125. this month, the salesperson has 25 signups. how many people did the salesperson call this month?

For every 8 people called, one signs up. So, for 25 signups you get 25*8=200 called people.

You are trying to find the halfway point between OO and NN.
OO: (-1,9)    NN: (-1,5)
The x-coordinate does not change, because in both instances it is -1. The y-coordinate is (9-5)/2 AWAY from each point. AKA the number that is equidistant from 5 and 9 (7).