First, you would need to determine the difference between last season's pear sales and this season's pear sales.
450 - 360 = 90
Next, you would need to create an equation to determine what percentage 90 is of 450. Let x represent the unknown sales decrease percentage.

=

Cross multiply.
450x = 9,000
Now, all you would need to do is isolate the x. To do this, you would divide both sides of the equal sign by 450.
x = 20
x =
20%The percent decrease was 20%.I hope this helps!