The number of dvds in a random person’s home collection is counted for a sample population of 80 people. the mean of the sample is 52 movies; the entire population is known to have a standard deviation of 12 movies. assuming a 99% confidence level, find the margin of error.

Use the elimination method to solve the system of equations -x+5y=-4 and 4x+3y=16

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.

Twenty points. suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet