Natasha makes on online purchase of 3 hard cover books for $19.95 each and 1 book on tape for $17.43. the site says that taxes paid by the customer are 7.25% of the total purchase price. shipping charges are based on the following table: amount of purchase standard shipping express shipping up to $50 $5.10 $7.00 $50 up to $100 $6.35 $8.20 $100 up to $200 $7.80 $11.60 $200 and over $10.50 $16.45 natasha selects standard shipping for her purchase and the company bills her credit card $91.08 for the total of the online purchase. determine if natasha has been billed correctly for her purchase. a. natasha has been billed correctly. b. natasha has not been charged enough for her purchase. c. natasha has been over charged by $1.85 for her purchase. d. natasha has been over charged by $8.20 for her purchase.