An event promoter reasons that if he charges $20 admission to see a new show, 1000 tickets will be sold. If he instead charges $30, the amount of tickets sold will be 600. What linear function p would model the number of tickets sold if this promoter charges p dollars per ticket. Explain the answer.

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”?