Question

The circumference of a circle varies directly as its diameter. When the diameter of a circle is 6 inches the circumference is 18.84 inches . Which equation describes y , the circumference of a circle when the diamete is x?

Answer 1

Spoilers!

This relation is PI or 3.14

Circumference / diameter is PI

so it should be 3.14159

and it is because 18.84/6 is 3.14

equation is y/x = 3.14

when y is circumference and x is diameter

Answer 2

6y=18.84x

Explanation:

Set up a proportion for the circumference to diameter ratio:

6/18.84=x/y

Cross multiply and you get the answer.