Question

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.

Answer 1

F(x) = $\left \{ {{1} \atop {3.5}} \right.$                        8.5≤
              0                                                             

Answer 2

Solution:

Mean life of i-pad mini= 10.25 hours

Formula for mean life = $e^\frac{-T}{d}}$, where d = Time Constant

Mean life of i-pad mini =  $e^\frac{-10.25}{d}}$

Battery life of the i pad mini is uniformly distributed between 8.5 and 12 hours.It can be written as

Pr (8.5 ≤ X ≤ 12)= $\int\limits^{12}_{8.5} {e^\frac{-10}{d}}} \, dx$, where , d= time constant.