Frank monitors the cost of gasoline for his budget. The table below shows Frank's gasoline purchases for the month of June. What was the average cost per gallon for gas during Week 4?

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”?