Problem of the Day At a concession stand

Problem of the Day At a concession stand, hamburgers are selling at a rate of 160 hamburgers per hour. The table shows the rate at which wraps are selling. Minutes 1 2 3 4 Wraps Sold 2. 5 5 7. 5 10 Concession Sales b. Graph equations that represent the growth rates of hamburgers sold and wraps sold in the same coordinate plane. Compare the steepness of the graphs. What does this mean in the context of the problem? Items Sold a. Do hamburgers or wraps sell faster? Explain. Minutes

When a straight line goes through (0, 0), it has a proportional relationship Origin The slope The constant of variation is ________ Also called the constant of proportionality y = constant x (y=kx) The equation looks like __________

The slope is __________ The rate of change Constant ______ Equation _______ Using k, write a proportion to find y when x = 24

Is this a proportional relationship? General Mills is coming out with a new cereal called Hot Cocoa. They experimented with some samples to decide their recipe. We will chart to samples. Co. Co Puffs Marshmallows What is the CONSTANT? How do you know? What would the equation be? 240 342

Identifying Direct Variation You need two things Constant SLOPE Origin (0, 0) Or check if the values form a proportion

If four Oreo cookies contain 220 calories. How many calories would be consumed if you eat three? Find the constant variation first. Write and use the equation to solve for three cookies.

Gallons of gas used Miles driven 2 56 3 84 4 100 5 128 6 154 Is this a proportional relationship? Explain your answer