To find the percent of change, you can use the following formula:
\[ \text{Percent of Change} = \frac{\text{New Value} - \text{Old Value}}{\text{Old Value}} \times 100 \]
In this case, the old value is $521.73 (original cost) and the new value is $413.68 (sale price).
Now, plug in the values:
\[ \text{Percent of Change} = \frac{413.68 - 521.73}{521.73} \times 100 \]
First, calculate the change in value:
\[ 413.68 - 521.73 = -108.05 \]
Now, divide that by the old value:
\[ \frac{-108.05}{521.73} \approx -0.2073 \]
Finally, multiply by 100 to convert to a percentage:
\[ -0.2073 \times 100 \approx -20.73 \]
The percent of change is approximately -20.73%. This indicates a decrease of about 20.73% in the price.