Hector's service club is rasing money by wrapping presents in the mall. the function f(x)=3x describes the amount of money, in dollars, the club will earn for wrapping x presents. they only have enough wrapping paper to wrap 1000 presents. describe the dependent variable.

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”?