Please help meh im so bad at this stuff lol

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.

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?

What is always true about a positive integer raised to a negative odd power?