Can someone me find the rest of the equation

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.

Gregory draws a scale drawing of his room. the scale that he uses is 1 cm : 4 ft. on his drawing, the room is 3 centimeters long. which equation can be used to find the actual length of gregory's room?

Jamie went to home depot. she bought 25 bags of soil that cost $9 per bag. she bought 15 pots at $8 each, and she bought 23 bags of pebbles at $15 each. she used a coupon that gave her $5 off for every 100 dollars she spent. how much did jame pay at the end?