Name______Level of Understanding_____

7ACC Linear Functions

Summative Assessment Part 2

  • I can determine the y-intercept of a function from a table, graph, equation, or real world scenario.
  • I can identify the slope and y-intercept of a real world situation and explain their meanings.
  • I can write an equation for a linear function that models a given real world situation.

  1. The Squeaky Clean Car Wash charges by the minute. This table shows the charges for several different times.

Squeaky Clean Car Wash Charges

Time (min) / 5 / 10 / 15 / 20 / 25
Charge / $8 / $13 / $18 / $23 / $28
  1. Write a function to model the relationship.
  1. Define the variables.
  1. What does the rate of change mean in terms of the context of the problem?
  1. What does the y-intercept mean in terms of the context of the problem?
  1. Suppose Greyhound Bus charges a $125 transportation fee plus $8.50 per passenger.
  1. Write a linear equation to represent this situation.
  1. What does the y-intercept represent in the context of this problem?
  1. What does the slope represent in the context of this problem?
  1. Write an equation to represent the graphs below.
  1. Below are 2 receipts from Squeaky Clean Car Wash. Assume the relationship between charge c and time used m is linear. The goal is to determine the cost per minute and the flat fee cost.

Date: 1-10-13
Start Time: 2:00 pm
Stop Time: 2:12 pm
Charge: $8.00
Date: 2-4-13
Start Time: 2:45 pm
Stop Time: 3:01 pm
Charge: $11.00

Each receipt represents a point (m,c) on the line.

Write an equation relating c and m.(Level 4)

  • I can explain how changing the slope affects the graph of a linear function.
  • I can explain how changing the y-intercept affects the graph of a linear function.

  1. Suppose you have the graph of . How would the graph of compare to ?
  1. Suppose you have the graph of . How would the graph of compare to ?
  1. Give an equation of a line that translates up 5 units. ______
  1. Give an equation of a line that makes twice as steep. ______
  1. Mrs. Golem and Mr. Grano are playing a math game similar to Battleship. Mrs. Golem starts by secretly graphing an equation. Mr. Grano tries to guess her equation. She responds, “Booooo! The graph of your equation is 4 units below mine, and the slope is ¾ of mine.” Give a possible equation for Mrs. Golem’s graph and a possible equation for Mr. Grano’s graph. (Level 4)

Mayfield City School District 8th Grade Math PLC 2012-13