Answer:
a. $18.36 for 3 pizzas : k = 6.12
b. $4.17 for 3 pounds of bananas . k = 1.39
c. $16.48 for 4 pounds of potatoes . k = 4.12
d. 2 cups of flour to make 24 cookie . k = 12
Step-by-step explanation:
PROPORTIONALITY:
Two quantities x and y are said to proportional to each other
if for x ∝ y , x = y k.
Here, k is called the PROPORTIONALITY CONSTANT.
⇒
Now, for the given quantities:
a. $18.36 for 3 pizzas [box]
Here, 
So, the proportionality constant is 6.12.
b. $4.17 for 3 pounds of bananas [box]
Here, 
So, the proportionality constant is 1.39.
c. $16.48 for 4 pounds of potatoes [box]
Here, 
So, the proportionality constant is 4.12.
d. 2 cups of flour to make 24 cookies
Here, 
So, the proportionality constant is 12.