Dependent vs Independent Variables

Molly harvests mushrooms in the forests of Oregon and then sells them to local restaurant chefs. The greater the weight of the mushrooms, the greater their value.

w = the weight of the mushrooms

v = the value of the mushrooms

• v is the independent variable and w is the dependent variable

• w is the independent variable and v is the dependent variable

A team from the Department of Public Works is painting lines of the freeway. The number of hours needed to finish the project depends on the length of road that needs to be lined.

h = the number of hours needed

r = the length of road

• h is the independent variable and r is the dependent variable

• r is the independent variable and h is the dependent variable

Zach and his friends are at an arcade and are redeeming their tickets for prizes. The number of prizes they can get is calculated based on how many tickets they have won.

p = the number of prizes the friends can get

t = the number of tickets the friends have won

• t is the independent variable and p is the dependent variable

• p is the independent variable and t is the dependent variable

While on vacation, Heather plans to write some postcards to her friends. The number of postcards she can send depends on how many stamps she has.

p = the number of postcards Heather can send

s = the number of stamps Heather has

• p is the independent variable and s is the dependent

• s is the independent variable and p is the dependent

What is the dependent variable in the equation y = 3x - 2?

• y

• x

• -2

• 3x

Which is the dependent variable?

• x

• y

• -1/2

• 4

A phone company charges a base rate of $40 a month for service. The user is charged $0.20 a minute for every minute used. The total amount charge to the customer, p, for any number of minutes, m, can be represented by the function
p = .2m + 40.
What is the dependent variable?

• The # of minutes used

• The base rate of $40

• The total amount charged to the customer

• The $0.20 per minute

Elizabeth hired a cleaning service to clean her house. To find C, the total cost of cleaning her house, she used the following equation.

C = 7.5x + 25

What is the dependent variable for the equation?

• 7.25

• 25

• C

• x

In the equation y = 2x - 4, what is the dependent variable?

• 2x

• x

• -4

• y

Which is the dependent variable?

• x

• y

• -1/2

• 4