Linear Models

Describe the value of the correlation coefficient.

• It is close to one.

• It is close to negative one.

• It is close to zero.

• There is no correlation between the quantities.

Which statement below accurately represents the graph?

• $100 is earned for each hour worked

• $100 is earned for every 2 hours worked

• $500 is earned for every 8 hours worked

• $200 is earned for every 3 hours worked

A DJ charges a setup fee plus an hourly fee to provide music for a dance party. Use the graph to write an equation in slope-intercept form to represent the amount spent, y, on x hours of music. 

• y = 75x + 100

• y = 100x

• y= 100x + 75

• y = 75x

Identify the slope and y-intercept of:
y = 1/2x - 1

• slope: 1/2   y-intercept:  -1 

• slope: 2/1   y-intercept:  -1

• slope: 3   y-intercept:  -3 

• slope: 2  y-intercept:  5 

The Roaming Cell Phone Company charges $15.00 per month plus $0.20 per minute of airtime usage.  If Juanita uses x minutes of airtime, what is an equation that can be used to determine her monthly cell phone bill (C)?

• C = 0.20x + 15

• C =15 (0.20x)

• C = 15 + x + 0.20

• C = 0.20 + 15x

Bob has $150 in his savings account and saves $40 per month. Which function models his savings?

• y = 150 + 40

• y = 40x + 150

• y = 150x + 40

A man is climbing down from 100 feet high descending 30 feet per minute. Which function models his descent?

• y = 100 - 30x

• y = 100 + 30x

• y = 100x + 30

• y = 100x - 30

The start up cost to join eTunes music is $7.95 plus $0.95 per song downloaded.  If Will spent $26, write and solve a linear equation to find how many songs he downloaded.

• 32 songs

• 33 songs

• 19 songs

• 36 songs

The total cost (y) at an amusement park can be modeled by y=1.5x+20 where x is the number of rides you ride. What is the price to ride 10 rides?

• 35

• 21.5

• 30

• 30.50