1 cm³ to hold 1 mm of water how many millimeters Wilbur aquarium below home how many liters

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.

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Nine more than four times a number is the same as one less than twice the number. find the number?