Find each product or quotient using significant digits. 11 ft × 825 ft

No. 4 , what’s a forty proportional?

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

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.