Look at Attachment, giving a lot of points for the answer to questions.

see below

Step-by-step explanation:

1.

m = (y2-y1)/(x2-x1)

    = (90-80)/(0-1)

     = 10/-1

   =-10

The slope is -10 ft/s

This means the height decreases 10 ft for every second that passes

This is not proportional because it has to go through the point (0,0)

4.

m = (y2-y1)/(x2-x1)

    = (1000-0)/(3-0)

     = 1000/3

   =1000/3

The slope is $1000/3

This means the 1000 dollars is sold every 3 days

This is proportional because it goes through the point (0,0) and has a constant slope

-2 is the right