Acomponent in a music system has a life expectancy of 2,400 hours with a standard deviation of 300 hours. if an average person listens to music for 1,000 hours in a year, the probability that the component lasts for more than 3 years is

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.

Write the equation for the parabola that has x− intercepts (−2,0) and (4,0) and y− intercept (0,4).

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.