The question is incomplete :
The amount sabrina earns varies directly with the number boxes of cookies she sells.How much does Sabrina earn for eah box of cookies that she sells?
Earning (y) : ____ 5 ____ 10 ____ 15 ____ 20
Boxes sold (x) :__ 2 ____ 4 _____ 6 ____ 8
Answer:
$2.5
Step-by-step explanation:
Given:
Earning varies directly as the number of boxes of cookies sold
y α x
y = kx - - - (1)
k = constant of proportionality (earning per box of cookies sold)
Taking any 2 points :
y = 10 ; x = 4
10 = k4
10 = 4k
Divide both sides by 4
10/4 = 4k/4
2.5 = k
Hence, the amount earned per box of cookies sold is $2.5
