Question

1. Based on the information in the table, is the cost of the apples proportional to the weight of apples?

Pound of apples:
2
3
4
5
Cost of apples:
$3.76
$5.64
$7.52
$9.40
2. Based on the information in the table, is the cost of the pizza proportional to the number of toppings?
Number of toppings:
2
3
4
5
Cost of pizza:
$11.99
$13.49
$14.99
$16.49

Answer 1

1. yes
2. no

Explanation:

When a number of similar calculations are required, a spreadsheet can reduce the tedium.

1. The price is a constant $1.88 per pound, so is proportional to the weight.

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2. The price is not proportional to the number of toppings.

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The cost of the pizza is $8.99 plus $1.50 per topping. The base cost being non-zero ensures that the overall cost is not proportional to the number of toppings.