The diameter of a plant at its equator is 267,100 kilometers. estimate using scientific notation

If x + 10 = 70, what is x? a. 40 b. 50 c. 60 d. 70 e. 80

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?

Can someone check if i did this correct. it’s number 4 if you’re wondering.