Direct Proportionality Concepts

The video explains the concept of direct proportion, where two variables increase or decrease at the same rate. It uses the example of hours worked and pay to illustrate this relationship. The video also describes how to graph direct proportion, highlighting that the graph is a straight line passing through the origin. It demonstrates using graphs to calculate earnings for different hours worked. The video concludes by summarizing the key points about direct proportion and its graphical representation.

What does it mean when two variables are directly proportional?

• One variable remains constant while the other changes.

• One variable increases while the other decreases.

• Both variables decrease at different rates.

• Both variables increase at the same rate.

In the example of hours worked and money earned, what happens if you work twice as many hours?

• You earn three times as much money.

• You earn twice as much money.

• You earn the same amount of money.

• You earn half as much money.

If you work 10 hours and earn 120 pounds, how much do you earn per hour?

• 15 pounds

• 12 pounds

• 20 pounds

• 10 pounds

What is the proportional symbol used to represent direct proportionality?

• Equal sign

• Greater than sign

• Proportional symbol

• Less than sign

What is the relationship between hours worked and money earned in the example?

• They are inversely proportional.

• They are constant.

• They are directly proportional.

• They are unrelated.

What is a key feature of a graph representing a direct proportionality?

• It passes through the origin.

• It is a horizontal line.

• It is a curved line.

• It has multiple peaks.

Why does a graph of direct proportionality pass through the origin?

• Because both variables start at zero.

• Because one variable is always negative.

• Because the graph is always a curve.

• Because the variables are unrelated.

In the context of the video, what does the origin represent on the graph?

• The point where the graph ends.

• The point where the graph is curved.

• The point where one variable is maximum.

• The point where both variables are zero.

What is the significance of the straight line in a direct proportionality graph?

• It indicates no relationship.

• It represents a non-linear relationship.

• It shows a variable rate of change.

• It indicates a constant rate of change.

How can you use a graph to find out earnings for a specific number of hours worked?

• By drawing a diagonal line from the origin.

• By drawing a line parallel to the y-axis.

• By drawing a horizontal line from the x-axis.

• By drawing a vertical line from the x-axis.