In ms. perron's class, 75% of the students are boys. there are 18 boys in the class. what is the total number of students in ms. perron's class

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!

Awasher and a dryer cost $701 combined. the washer costs $51 more than the dryer. what is the cost of the dryer?