Real word problem ⇒ constant of proportionality
$4.16 for 4 pounds of bananas ⇒ 1.04
$16.48 for 8 pounds of potatoes ⇒ 2.06
$18.36 for 2 pizzas ⇒ 9.18
2 cups of flour to make 36 cookies ⇒ 18
<em><u>Solution:</u></em>
A proportional relationship is one in which two quantities vary directly with each other.
We say the variable y varies directly as x,
if for x ∝ y
then, x = y k
Where "k" is called constant of proportionality
<em><u>$4.16 for 4 pounds of bananas</u></em>
x = 4.16 and y = 4
Thus constant of proportionality is 1.04
<em><u>$16.48 for 8 pounds of potatoes</u></em>
x = 16.48 and y = 8
Thus constant of proportionality is 2.06
<em><u>$18.36 for 2 pizzas</u></em>
x = 18.36 and y = 2
Thus constant of proportionality is 9.18
<em><u>2 cups of flour to make 36 cookies</u></em>
x = 36 and y = 2
Thus constant of proportionality is 18