how does the calculated slope reflect what we see on the graph?

Dollars $3,500,000,000 $3,000,000,000 $2,500,000,000 $2,000,000,000 $1,500,000,000 $1,000,000,000 $500,000,000 $- Mayo y=-5213.3x + 5E+09 R = 0.0882 y=-5241.2x+4E+09 R = 0.2267 340,000 350,000 360,000 370,000 Volume 380,000 390,000 400,000 Total Revenues Total Expenses Linear (Total Revenues) Linear (Total Expenses)