How do I calculate the Linear approximation from this graph? Can you show me, please? Thank you!

https://www.coursehero.com/qa/attachment/39159119/?__chid=21224cbc-26f8-4272-a97b-571a6aa77fdc

Screen size in inches Prices in $$ (rounded to a whole number of dollars)

24 168, 170, 160, 32 200, 180, 200, 198, 180 40 230 43 380, 430, 430, 370, 400, 330 50 550, 550, 548, 460, 430 55 550, 600, 650, 598, 500, 600, 550 65 700, 898, 700, 750, 850, 898, 848, 750 70 1300, 1200, 1198, 1300 75 1 500, 1498, 1198, 1275, 1300 85 2198, 1798, 1698, 1998, 1800