Difference between 4 and - 4​

Angela rode his bike around a bike trail that was 1/4 of a mile long he rode his bike around the trail 8 * angelo says he wrote a total of 8/4 miles to russell says he's wrong and he actually and says that he actually wrote to my who is corrupt use words and trying to explain how you know.

The number of potato chips in a bag is normally distributed with a mean of 71 and a standard deviation of 2. approximately what percent of bags contain between 69 and 73 potato chips? approximately 68% approximately 71% approximately 95% approximately 99.7%

Abook store is having a 30 perscent off sale. diary of the wimpy kid books are now 6.30 dollars each what was the original price of the books