Engineers want to design seats in commercial aircraft so that they are wide enough to fit

90%

of all males. (Accommodating 100% of males would require very wide seats that would be much too expensive.) Men have hip breadths that are normally distributed with a mean of

14.3

in. and a standard deviation of

1.2

in. Find

P90.

That is, find the hip breadth for men that separates the smallest

90%

from the largest

10%