To find the percent of change (in this case, a decrease) of the sweater's price, we use the formula:

$\text{Percent of Change} = \left( \frac{\text{Original Price} - \text{Sale Price}}{\text{Original Price}} \right) \times 100$

Here:

• Original Price = $80
• Sale Price = $30

Now, plug the values into the formula:

$\text{Percent of Change} = \left( \frac{80 - 30}{80} \right) \times 100 = \left( \frac{50}{80} \right) \times 100$

$\text{Percent of Change} = 0.625 \times 100 = 62.5\%$

So, the percent of change is 62.5%.

Would you like more details on this calculation or have any questions?

Here are 5 related questions to explore:

1. If Michael received an additional 10% discount, what would be the new sale price?
2. If the sweater had been discounted by 75%, what would the sale price have been?
3. What would the percent of change be if the sale price was $50 instead of $30?
4. If Michael bought two sweaters, what would the total savings be?
5. What is the formula for calculating percent increase?

Tip: Always make sure to subtract the sale price from the original price to avoid confusion when calculating percent decrease!