The lifetimes of all the batteries produced by a certain company in a year have a distribution that is symmetric about the mean m. If the distribution has a standard deviation of d, what percent of the distribution is greater than m+d?
(1) 68 percent of the distribution lies in the interval from m-d to m+d inclusive
(2) 16 percent of the distribution is less than m-d
Can someone please explain? Many Thanks.
(1) 68 percent of the distribution lies in the interval from m-d to m+d inclusive
(2) 16 percent of the distribution is less than m-d
Can someone please explain? Many Thanks.
