pls help with hw question

Homework: H... estion 2 Part 1 of 4 O Points: 0 of 1 Steel rods are manufactured with a mean length of 20 centimeter (cm). Because of variability in the manufacturing process, the lengths of the rods are approximately normally distributed with a standard deviation of 0.06 cm. Complete parts (a) to (d). (a) What proportion of rods has a length less than 19.9 cm? (Round to four decimal places as needed.)