8.16c Recap

Joshua is playing a video game. The more time Joshua spends on the game, the more levels of the game he passes. Which of these is the independent variable in this situation?

• The levels Joshua passes
• The time Joshua plays
• The number of levels the game has
• The number of points he scores

Which TWO scenarios correctly identify the dependent variable?

• Maria and Calvin have a business designing websites for small businesses. The more business they work with, the greater their earnings. The dependent variable is the amount of their earnings.
• Jason has discovered that if he watches his diet, he performs better while running. The less sugar he eats, the lower his racing time. The dependent variable is the amount of sugar Jason eats.
• A construction manager notices that the longer a project takes to complete, the higher the labor costs. The dependent variable is the length of time it takes to complete a project.
• The greater the number of hours of daylight in a day, the more time Roger spends on yardwork. The dependent variable is the time Roger spends working in the yard.

Mr. Roberts hired an electrician to work on his home. The cost of the electrician, C, was $30 for the service call, plus $35 for each hour’s work, h. Identify the independent variable in this equation.

• c
• h
• 30
• 35

Mr. Roberts hired an electrician to work on his home. The cost of the electrician, C, was $30 for the service call, plus $35 for each hour’s work, h. Identify the dependent variable in this equation.

• c
• h
• 30
• 35

Select ALL correct answers. The formula for the volume of a cone is shown below, where r is the radius of the cone's base and h is the height of the cone. Which are the independent variables?

• The height of the cone (h)
• 1/3
• The radius of the base (r)
• The volume of the cone (V)

A frequent traveler kept careful records of fuel consumption. The scatterplot below shows the amount of fuel used and the amount of fuel remaining in the gas tank. Based on this model, what is the dependent variable?

• The number of gallons the tank holds
• The number of gallons of remaining fuel
• The number of gallons of fuel used
• The number of miles traveled

Every year on your birthday, one of your relatives gives you $1 for every year of your age. Which is the independent variable?

• Your age
• Amount you receive each year
• Total amount received
• The month of your birth

A travel agent provides a discount based upon the amount of money a client spends. The discount program is outlined in the table below. What is the independent variable?

• the percent of the discount
• the amount of the discount
• the length of the trip
• the amount of the travel package

James has $50 in his lunch account. He will use $3.10 to buy lunch each day. The equation below shows how he will calculate the amount remaining in his lunch account, a, after each day’s lunch, l. Which of the following is the independent variable?

• a
• 50
• 3.1
• l

The formula for the surface area of a square-based pyramid is shown below, where l is the slant length, p is the perimeter of the base, and B is the area of the base. What is the dependent variable?

• the area of the base, B
• the perimeter of the base, p
• the slant length, l
• the surface area, SA