Question

pounds of apples cost of apples 2 $3.76 3 $5.64 4 $7.52 5 $9.40 number of toppings cost of pizza 2 $11.99 3 $13.49 4 $14.99 5 $16.49 1) Based on the information in the table, is the cost of the apples proportional to the weight of apples? Show your work. 2) Based on the information in the table, is the cost of the pizza proportional to the number of toppings? Show your work 3) Write an equation for the proportional relationship.

Answer 1

For the first table, we notice that:

$\frac{2}{3.76}=\frac{3}{5.64}=\frac{4}{7.52}=\frac{5}{9.40}\text{.}$

Therefore, the cost of the apples and the number of apples have a proportional relationship.

For the second table, we notice that:

$\frac{2}{11.99}\ne\frac{3}{13.49}.$

Therefore, the cost of the pizza and the number of toppings are not proportional.

Answer:

(a) The cost of the apples is proportional to the weight of the apples.

(b) The cost of the pizza is not proportional to the number of toppings.

(c) Let p be the number of pounds, and c be the cost in dollars, then we can set the following equation:

$c=1.88p\text{.}$