The total sales made by a salesperson was $25,000 after 3 months and $68,000 after 23 months. Using an equation for the line whose graph depicts this data, predict the total sales after 40 months

Answer 1

Sales total increases 43,000/20 = 2150 per month.

You don't say whether this is monthly sales or cumulative sales.

If m is the month number and S the total sales,

S = 22,850 + 2150*(m-2)
= 2150 m + 18,550