Mark buys a wooden board that is 7 1/2 feet long. The cost of the board is $0.50 per foot, including tax. What is the total cost, in dollars, of Mark’s board?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?