jointly proportional


Definition of Jointly Proportional

  • If a variable z is jointly proportional to a set of variable x and y, the z = kxy, where k is the constant of proportionality.

 More about Jointly Proportional

  • Jointly proportional is also known as joint variation.

Example of Jointly Proportional

  • The kinetic energy, E, of a moving object is jointly proportional to its mass, m, and the square of its speed, v.i.e., E = k .m. v2

Solved Example on Jointly Proportional

If x is jointly Proportional to y and z when x = 4, y = 8 and z = 9, then find the value of x when y = 2 and z = 18.
Choices:
A. 1
B. 0
C. 2
D. 4
Correct Answer: C
Solution:
Step 1: x a k. y. z [joint proportional]
Step 2: x = k. y. z
Step 3: 4 = k. 8. 9 [Substituting the values for x, y, z.]
Step 4: k = [Simplify.]
Step 5: Therefore, x =. 2. 18 [Substituting the values for k, y and z in x = k. y. z]
Step 6: So, x = 2 [Simplify.]

Related Terms for Jointly Proportional

  • Constant of proportionality
  • Direct proportional
  • Variables