When the number z is multiplied by 5, the result is the same as when 5 is added to z. What is the value of 4z?

Zahra was given two data sets, one without an outlier and one with an outlier. data without an outlier: 15, 19, 22, 26, 29 data with an outlier: 15, 19, 22, 26, 29, 81

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?

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?