Answer:
D = .44P
Explanation:
We need to find the slope of the line
m = (y2-y1)/ (x2-x1)
Using two points
m = (22-4.4) /(50-10)
= 17.6/40
= .44 lb/ in^2 ft
We can use the point slope form of the equation
y-y1 = m(x-x1) where y=D and x=P
D-4.4 = .44 (P-10)
Distribute
D-4.4 = .44P - 4.4
Add 4.4 to each side
D -4.4+4.4 = .44P -4.4+4.4
D = .44P