In october 2012, apple introduced a much smaller variant of the apple ipad, known as the ipad mini. weighing less than 11 ounces, it was about 50% lighter than the standard ipad. battery tests for the ipad mini showed a mean life of 10.25 hours (the wall street journal, october 31, 2012). assume that battery life of the ipad mini is uniformly distributed between 8.5 and 12 hours. a. give a mathematical expression for the probability density function of battery life.