How large of a sample must be drawn so that 98% confidence interval for μ will have a margin of error equal to $133 and σ=$530

Which of the following properties can be used to show

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.

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1