The Unruly Queens chess club is hosting a tournament, and each club member is bringing something to eat or drink. Kristen decides to bring oatmeal raisin cookies from her favorite bakery.

There is a proportional relationship between the number of oatmeal raisin cookies Kristen buys, x, and their total cost (in dollars), y.
x (cookies) y (dollars)
10 $10
11 $11
17 $17
19 $19
What is the constant of proportionality? Write your answer as a whole number or decimal.

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
3 hours ago

In a proportional relationship, the ratio of the total cost \( y \) to the number of items \( x \) remains constant.

From the information provided, we can determine the constant of proportionality by examining the relationship using any pair of values from the table.

Let's take the first pair:

  • For 10 cookies, the cost is $10.

Calculating the ratio: \[ \text{Constant of proportionality} = \frac{y}{x} = \frac{10}{10} = 1 \]

Next, we can verify this with other pairs:

  • For 11 cookies, the cost is $11: \[ \frac{11}{11} = 1 \]

  • For 17 cookies, the cost is $17: \[ \frac{17}{17} = 1 \]

  • For 19 cookies, the cost is $19: \[ \frac{19}{19} = 1 \]

In each case, the total cost divided by the number of cookies equals 1.

Thus, the constant of proportionality is \( \boxed{1} \).