Cade had 4 yd board the answer is 8 what is the question

What is the average rate of change for this function for the interval from x=2 to x=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”?

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount