The table lists how financial aid income cutoffs (in dollars) for a family of four have changed over time. use the midpoint formula to approximate the financial aid cutoff for 1985.
year. income
1960. 21,250
1970. 27,500
1980. 33,750
1990. 40,000
2000. 46,250

You can see that every decade the income increases by 6,250. So if you want to do 5 years instead you would have to add 3,125 to the income of 1980 to find what the income was for 1985. Now you add 33,750+3,125= 36,875. The financial aid cutoff for 1985 would be $36,875.

Abit confused about what you mean, but i think you might be referring to slope intercept form: y = mx + bin that case b, or the y intercept is already given.(0,-1)find the slope by using the formulay2 - y1/x2 - x1the final slope will be 4/2, equivalent to 2.now your equation should look like thisy = 4/2x -1sorry if this didn’t you out!