A sample of $65$ electric motors had a mean efficiency of $0\mathrm{.}595$ with a standard deviation of

$0\mathrm{.}05.$ Let $\backslash$mu represent the mean efficiency of electric motors of this type.

Either the mean efficiency is less than $0\mathrm{.}6,$ or the sample is in the most extreme

$\_\_\_\_\_\%$ of its distribution.