Find volume of sphere. than round it to nearest hundredths

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”?

The function p(x) = –2(x – 9)2 + 100 is used to determine the profit on t-shirts sold for x dollars. what would the profit from sales be if the price of the t-shirts were $15 apiece?

Find the area of the shaded region.