Question

I need a answer!

4 glue sticks cost $7.76.
which equation would help determine the cost of 13 glue sticks
choose 1 answer:
A x/13 = 4/$7.76
B 13/x = $7.76/4
C 4/$7.76 = 13/x
D 13/4 = $7.76/x
E None of the above

Answer 1

C

Explanation:

We know that the cost of a glue stick is proportional to the quantity

Thus, you could create a proportion for 4 glue sticks costing $7.76 (4 / 7.76) and 13 glue sticks costing $x (13 / x), where you'd need to solve for x by cross multiplying:

`(4)/(7.76)=(13)/(x)\\ \\ 4x=100.88\\x=25.22`

When we do the math, we see that 4 / 7.76 simplifies to about 0.51 and 13 / 25.55 also simplifies to about 0.51, showing the the two fractions are proportional.