Steel rods are manufactured with a mean length of 27 centimeter​ (cm). Because of variability in the manufacturing​ process, the lengths of the rods are approximately normally distributed with a...

Steel rods are manufactured with a mean length of

centimeter​ (cm). Because of variability in the manufacturing​ process, the lengths of the rods are approximately normally distributed with a standard deviation of

cm.

​(a) What proportion of rods has a length less than

​cm?