You talk to a friend who lives in a different state. she tells you that today it is 12° below zero where she lives. you tell her it is 54° where you live. what is the difference in temperatures?

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”?