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.

Gas mileage actually varies slightly with the driving speed of a car (as well as with highway vs. city driving). suppose your car averages 33 miles per gallon on the highway if your average speed is 54 miles per hour, and it averages 22 miles per gallon on the highway if your average speed is 75 miles per hour. answer parts (a) and (b) below. a. what is the driving time for a 2000-mile trip if you drive at an average speed of 54 miles per hour? what is the driving time at 75 miles per hour? the driving time at 54 miles per hour is nothing hours. (type an integer or decimal rounded to two decimal places as needed.) the driving time is at 75 miles per hour is nothing hours. (round to two decimal places as needed.) b. assume a gasoline price of $3.33 per gallon. what is the gasoline cost for a 2000-mile trip if you drive at an average speed of 54 miles per hour? what is the gasoline cost at 75 miles per hour? the gasoline cost at 54 miles per hour is $ nothing. (round to two decimal places as needed.) the gasoline cost at 75 miles per hour is $ nothing. (round to two decimal places as needed.)