Directly and Inversely Proportional Equations

A person’s weekly pay is directly proportional to the number of hours worked. Shawn’s pay is $123.00 for 20 hours of work. What is the constant of variation?

• k = 123

• k = 20

• k = 6.15

• k = 0.16

A is inversely proportional to the square root of B

If y varies directly as the square of x, how y is changed if x is increased by 20%?

• 0.44% decreased in y

• 0.44% increase in y

• 44% decreased in y

• 44% increase in y

Which of the following equations describe a direct variation?

• y = kx

Which of the following statements best illustrates an inverse variation?

• The length of a rectangular field with constant area varies inversely as its width.

• The electrical voltage varies jointly as the current I and the resistance R.

• The area of a triangle is directly proportional to its height.

• P varies directly as the square of x and inversely as s.

Which table of values represent the equation y = 18/X

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The statement “w varies directly as x and a square of y and inversely as z” can be written as:

Find the equation of variation that describes the relationship of the two quantities given in the graph.

• y=kz

• y=10z

In the statement“s varies inversely as a”, s = 3 when a = 9.What is the value of s when a = 4?

The volume (V) of a sphere varies directly as the cube of its radius (r). The volume is 36π when the radius is 3. What radius would produce a value of 288 π?

• 3

• 4

• 5

• 6