Interpreting Slope as Unit Rate

Ryan buys his lunch in the school cafeteria. The cost of 15 school lunches is $33.75. Which graph has a slope that best represents the average cost of the lunches in dollars per lunch?

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Melanie pays a total of $16.50 for every 6 shirts she has dry cleaned. Which graph models a relationship with the same unit rate?

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Mrs. Soto can decorate 5 cupcakes in 2 minutes.

Which graph has a slope that best represents the

number of cupcakes per minute Mrs. Soto can

decorate?

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Haydn makes $10 for every 2 glasses of

lemonade he sales. Which graph models a

relationship with the same unit rate?

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Reed is measuring a tomato plant in his mother’s

garden. The plant grew 15 inches in the first 3

months after it was planted. If the plant continues to

grow at the same rate, which graph best represents

the growth rate of the plan in inches per month?

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A scuba diver is descending at a rate of 15 ft per

minute. Which graph has a slope that best

represents this rate?

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Jose road his bike to his friend’s house that was

9 miles away. It took him 30 minutes to get there.

Which graph has a slope that best represents the

distance traveled and the time?

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Ethan drove 75 miles using 3 gallons of gas.

Which graph models a relationship with the same

unit rate?

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This graph shows a proportional relationship between time in hours and total cost in dollars. If you were to add 5 to all of the y values would there still be a proportional relationship? Explain.

• Yes, time and money are always proportional.

• No, you have to add 5 to all of the x values in order to keep the proportional relationship.

• Yes, if you were to add 5 to all of the y values the line would still pass through the origin and have a constant unit rate of change the slope would be the same.

• No, if you were to add 5 to all of the y values the line would no longer pass through the origin however it would still have a constant unit rate of change.

What is the unit rate for the graph shown? Be sure to type your answer in the form (slope, y-axis label) per (x-axis label)!