If you would like to know what was the percent decrease in price, you can calculate this using the following steps:
x% of $299.99 is $180.55
x% * 299.99 = 180.55
x/100 * 299.99 = 180.55
x = 180.55 * 100 / 299.99
x = 60.19%
100% - 60.19% = 39.81%
The correct result would be 39.81%.