Which variable is something you can choose to change? Can you choose the total costs of the snacks purchased? Can you choose how many snacks to purchase?
Independent Variable: Number of snacks purchased Dependent Variable: Total cost In Words: See solution. Equation: C=18+3s Graph:
Practice makes perfect
Because the total cost of the game changes in response to the number of snacks we choose to purchase, the total cost is the dependent variable and number of snacks purchased is the independent variable. We will begin with putting the given information into words, and then we can create an equation that we can graph.
In Words
Before we can begin, we need to observe the changes in each row of the data.
Originally the total cost is $18, and the total cost increased by $3 every time a snack is purchased. Let's express this verbally.
The total cost of the game
is equal to the original$18
plus$3per snack purchased.
Equation for the Relationship
To write an algebraic equation to describe the relationship, we will translate the verbal expression we created above.
Total Cost=original $$18$+$3per snack
We were given the starting cost and we determined the cost per snack. We will use the variable C to represent the total cost and s to represent the number of snacks purchased. Then we can write our equation in algebraic terms.
C=18+3s
Graph of the Relationship
To show the data graphically, begin by plotting the points on a coordinate plane.
Please note that this function is discrete because we usually cannot purchase a portion of a snack. We buy them in integer amounts.
