Exploring Percent Increase and Decrease

This video tutorial explains how to solve percent increase and decrease problems using proportions. It highlights the importance of correctly setting up the proportion by placing the new value over the old value and equating it to the percent over 100. The tutorial provides two examples: calculating the percent decrease in the price of a sofa and the percent increase in a town's population. The key takeaway is to use the absolute value of the difference between the old and new values over the old value to find the percent change.

What is the first step in solving percent increase or decrease problems?

• Calculate the new value

• Multiply the values

• Set up the proportion correctly

• Identify the percent value

What does the proportion for percent decrease compare?

• Percent to 100

• New value to percent

• Absolute difference to old value

• New value to old value

How do you find the absolute difference in the context of percent decrease?

• Subtract old from new

• Add old and new

• Divide old by new

• Subtract new from old

What mathematical operation is used to solve the proportion after setting it up?

• Addition

• Division

• Multiplication

• Subtraction

What was the percent decrease from $299 to $179?

• 30%

• 25%

• 50%

• 40.13%

In the context of population increase, what does the old value represent?

• The percent increase

• The difference in population

• The initial population

• The new population

How is the absolute value used in calculating percent increase?

• It is added to the old value

• It is subtracted from 100

• It represents the difference ignoring sign

• It is divided by the new value

What is the result of the proportion calculation for the population example?

• 100%

• 200%

• 154.48%

• 50%

What does the denominator in the proportion typically represent in these problems?

• The absolute difference

• The percent value

• The new value

• The old value

What is the correct interpretation of a percent decrease in the context of the examples given?

• The initial value

• An increase in value

• No change in value

• A reduction in value