Introduction to Direct Proportion

The video tutorial introduces the concept of direct proportion, explaining how two values increase at the same rate. It covers the mathematical representation of direct proportion using the equation y = kx, where k is the constant of proportionality. The tutorial provides examples, such as calculating the circumference of a circle using pi, and solving direct proportion problems by finding the constant k. Advanced problems involving squared terms are also discussed. The importance of setting up equations correctly is emphasized throughout the tutorial.

What does it mean when two values are in direct proportion?

• One value remains constant while the other changes.

• Both values decrease at the same rate.

• One value increases while the other decreases.

• Both values increase at the same rate.

In the context of direct proportion, what does the constant of proportionality (k) represent?

• The rate at which one value changes with respect to the other.

• The sum of the two values.

• The product of the two values.

• The difference between the two values.

Which of the following is an example of direct proportion?

• The relationship between mass and volume for a fixed density.

• The relationship between temperature and pressure in a closed system.

• The relationship between the circumference and diameter of a circle.

• The relationship between speed and time for a constant distance.

If y is directly proportional to x and y = 20 when x = 4, what is the value of k?

• 4

• 5

• 6

• 8

Given p is directly proportional to t, and p = 24 when t = 8, what is the equation relating p and t?

• p = 2t

• p = 3t

• p = 5t

• p = 4t

In a direct proportion problem where d is proportional to s squared, if d = 900 when s = 20, what is the value of k?

• 3.5

• 1.5

• 4.25

• 2.25

For the equation d = 2.25 * s^2, what is the value of d when s = 25?

• 1,750.00

• 1,625.00

• 1,500.00

• 1,406.25