What is the y-intercept of the line that models this situation?

Since the slope is consistent the y intercept would be 70.

You can try drawing a line connecting the other dots and see what crosses the y intercept.

But if you want to do the actual math the formula is y=mx+b. B being the y intercept.

So find slope (rise over run) or (y2-y1)/(x2-x1) I’ll choose (1, 65) (2, 60)
m= 60-65/2-1= -5/1= -5.
Negative also means the line is sloped down.

Plug the slope back into the formula using one of the points to substitute.

Using (1,65) into y=mx+b
65=-5(1)+b
65 =-5+b
65+5=b
b= y-intercept= 70