Marie pays $2.50 for 5 pencils. Use the drop-down menus to explain how to determine and

use the constant of proportionality, in dollars per pencil, that relates these values.

k = 0.5 or 1/2

y = 0.5 x

Step-by-step explanation:

Constant of proportionality is the ratio between two quantities that are directly proportional. The constant value usually represented with letter k relates amount that falls and rise uniformly. In a situation where we have the ratio of a and b, the constant can be represented as k = a/b

Marie pays $2.50 for 5 pencils. Using the constant of proportionality, in dollars per pencil that relates this value,

The constant of proportionality (k) equals the total amount (y) of the pencil divided by the number of pencils (x).

k = y/x

y = 2.5

x = 5

k = 2.5/5

k = 0.5

y = kx

y = 0.5 x