Interpreting Slope and Y-Intercept on a Graph

Which of the following situations could be descried by the equation y= -25x + 120

• There are 120 people in the football stadium, and 25 more are entering each hour.

• A plumber charges $25 for a house call and $120 per hour.

• A teacher has 120 students. Her third period has 25 students

• There are 120 gallons of water in a tank. It releases water at a rate of 25 gallons per minute

What is the meaning of the slope?

• The cost to get into the fair is $5

• The total cost for the day will increase by $1.75 for every ride you go on.

• The cost to get into the fair is $1.75

• The total cost for the day will increase by $5 for every ride you go on. 

An air conditioning saleman earns a base salary plus a commission for each air conditioner her sells. The equation y = 375 + 125x represents his pay based on the number of air conditioners he sells each week. What is the slope and what does it represent?

• The slope is 375 and represents the amount he earns for each air conditioner.

• The slope is 125 and represents the amount he earns for each air conditioner.

• The slope is 375 and represents the base salary.

• The slope is 125 and represents the base salary.

• The slope is $850/car and it represents the commission per car sold.

• The slope is $425/car and it represents the commission per car sold.

• The slope is $1500 and it represents the monthly salary before commission.

• The slope is $850 and it represents the monthly salary before commission.

What does the y-intercept represent?

• The amount of each deposit made

• The initial amount of money in the savings account

• The number of deposits made

• The amount of money in the savings account after 50 deposits

What does the slope mean in the context of the problem?

• The cost will increase by $1.40 per topping

• The cost will decrease by $1.40 per topping

• The cost will increase by $1.90 per topping

• The cost will decrease by $1.90 per topping

The graph represents the height of a burning candle.  What is the meaning of the y-intercept?

• the time it takes to burn the entire candle

• the rate at which the candle is losing height

• the change in the height of the candle each hour

• the original height of the candle

What line has the steepest slope?

• All slopes are equal

• Red

• Blue

• Green

What does the rate of change represent?

• The population increased 5,700 every year

• The initial population was 193,000

• The population decreased 5,700 every year

• The population increased 193,000 every year

Interpret the meaning of the slope of the graph below.

• $2 for every 1 mile driven

• $1 for every 2 miles driven

• 2 miles driven for $1

• 1 mile driven for $2