What two integers does √18 fall between?

A 2 and 3
B 4 and 5
C 6 and 8
D It is exactly 3.5
E It is exactly 9

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.