Answer:
The amount of the discount is calculated by multiplying the subtotal by 15%:
discount = 0.15 x 85.28 = 12.79
The new subtotal after the discount is applied is:
new subtotal = 85.28 - 12.79 = 72.49
The tax on the new subtotal is calculated by multiplying the new subtotal by 6.5%:
tax = 0.065 x 72.49 = 4.71
The final bill, including the tax, is the sum of the new subtotal and the tax:
final bill = 72.49 + 4.71 = 77.20
Therefore, the final bill after the coupon is applied and the tax is paid is $77.20.