Price of the online item bought by someone in Arizona = $22.50
Percentage of state sales tax that needs to be paid = 6.6%
Then
Amount of sales tax that needs to be paid = (6.6/100) * 22.50
= 148.5/100 dollars
= 1.48 dollars
So
The final price that needs
to be paid for the online item = (22.50 + 1.48) dollars
= 23.98 dollars