Final answer:
Mary saved 58.92 by purchasing tires through mail order instead of buying at a local store, which does not match the provided options.
Step-by-step explanation:
The question is about the cost savings Mary would have by purchasing tires through mail order versus buying them at a local store. First, we calculate the total amount Mary paid for the tires she purchased by mail order. She bought 4 tires at 49.60 each, with shipping and handling at 5.80 per tire, and mounting and balancing at 7.98 per tire. This equals 63.38 per tire, for a total of 253.52 for all four tires.
In contrast, at the local store, the total for the tires with mounting and balancing would be 292 before tax. With a 7% sales tax, the total comes to 312.44. Now, let's find out how much Mary saved by purchasing the tires through mail order: 312.44 (local store price with tax) - 253.52 (mail order price) = 58.92. Therefore, Mary saved58.92 by purchasing the tires through the mail, which is not one of the options provided.