Constant of Proportionality 7.4C

As a school carnival, tickets can be purchased to participate in different activities. The table shows the total cost for different numbers of tickets. What is the constant of proportionality that relates, y the total cost in dollars to x, the number of tickets purchased?

• 4.00

• 0.25

• 1.00

• 0.10

A recipe says to use 3 cups of flour to make 48 cookies. The constant rate of proportionality that relates the number of cookies made, y, to the number of cups of flour used, x, is ______.

The cost of 3 pounds of grapes is $6.57. What is the constant of proportionality that relates the cost in dollars, y, to the number of pounds of grapes, x?

• 6.57

• 3

• 2.19

• Not here

The graph shows the proportional relationship between the number of hours worked and the total pay for working at the ball park. The constant of proportionality is ____.

Consider the equation y = kx where y = 7.5 and x = 3. What is the value of k, the constant of proportionality?

• 22.5

• 4.5

• 0.4

• 2.5

Haley and Keri are setting up tables for a party. It takes them 15 minutes to set up 5 tables. If Haley and Keri work at a constant rate, the constant of proportionality would be ___.

Mark is a rock climber. His height, in feet, when climbing a wall can be represented by the equation h = 15t, where t is time measured in hours. Which best describes this proportional relationship?

• Mark moves 15 feet per hour.

• Mark moves $\frac{1}{4}$ feet per hour.

• Mark moves 4 feet per hour.

• Mark moves $\frac{1}{15}$ feet per hour.

Your dad is filling the family pool with water for the summer. After two hours, the water has reached a depth of 2.5 feet. After three hours, the water level has risen to

 $3\ \frac{3}{4}$  feet.  If the relationship between time and water depth is proportional, the constant of proportionality is ___.

Brooklyn is running a 5K. Her mom records her time at three places during the race as shown in the table. If Brooklyn runs at a constant rate per minute, which statement best describes the constant of proportionality?

• Brooklyn runs $\frac{1}{6}$ kilometer per minute.

• Brooklyn runs $\frac{3}{2}$ kilometers per minute.

• Brooklyn runs 6 kilometers per minute.

• Brooklyn runs $\frac{2}{3}$ kilometer per minute.

Ryan's science class conducts an investigation in which the measure the distance a toy car travels in seconds. The results of the investigation are shown in the graph. The constant of proportionality for this investigation is ____.