Question

Indira makes a graph to show how many

pages of her graphic novel she can illustrate
each day.
What is the constant of proportionality for
the relationship between pages and days?

Answer 1

A. ¾

B. 7½ pages

Explanation:

A. Constant of proportionality, k, =
`(y)/(x)`

In this case, y = pages, while x = days.

Take any coordinate pair to calculate the constant of proportionality, k. Let's use (3, 4).

`k = (y)/(x) = (3)/(4)`

Constant of proportionality = ¾.

B. Number of pages (y), Indira would read in 10 days (x).

Substitute x = 10 and k = ¾, into
`k = (y)/(x)`

`(3)/(4) = (y)/(10)`

Multiply both sides by 10

`(3)/(4)*10 = (y)/(10)*10`

`(3)/(2)*5 = y`

`(15)/(2) = y`

`7(1)/(2) = y`

Number of pages Indira can read in 10 days is 7½ pages.