What is the first step to locating the incenter of a triangle?

According to the normal model, what percent of receivers would you expect to gain fewer yards than 2 standard deviations below the mean number of yards

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.

Can someone me with this graph problem by the way i need to know the answers by today since this assignment is due ! !