Since the cost of the ball is $9.29
The discount is 11.25%
Means the new price will be 100% - 11.25% of the cost
Then the new cost = 88.75% * 9.29
The new cost = 8.244875
This cost will increased by the tax
Since the tax is 6.25%
Then 100% + 6.25% = 106.25%
So the final price = 106.25% * 8.244875
The final price = 8.78 079
The final price = 8.78
