The table on the far left
You can tell because every time the x value increases by 1, the y value increases by exactly 1/2 every time
Answer:

Step-by-step explanation:
Given
Length of string = x inches
Required
Determine the length in yards
Represent the equivalent length with y
Such that

Divide x by 36 to get equivalent in yards


Hence, the equivalent in yards is 
Given: 3y cos x = x² + y²
Define

Then by implicit differentiation, obtain
3y' cos(x) - 3y sin(x) = 2x + 2y y'
y' [3 cos(x) - 2y] = 2x + 3y sinx)
Answer:
(2·3.5 + 4·3.25 + 2·1.9 + 1·1.2)·(1 - 0.05) = $23.75