Question

Steel rods are manufactured with a mean length of 29 centimeter​ (cm). Because of variability in the manufacturing​ process, the lengths of the rods are approximately normally distributed with a standard deviation of 0.08 cm. Complete parts ​(a) to ​(d).

​(a) What proportion of rods has a length less than 28.9 ​cm? nothing ​(Round to four decimal places as​ needed.)

​(b) Any rods that are shorter than 28.81 cm or longer than 29.19 cm are discarded. What proportion of rods will be​ discarded? nothing ​(Round to four decimal places as​ needed.) ​

(c) Using the results of part ​(b)​, if 5000 rods are manufactured in a​ day, how many should the plant manager expect to​ discard? nothing ​(Use the answer from part b to find this answer. Round to the nearest integer as​ needed.) ​

(d) If an order comes in for 10 comma 000 steel​ rods, how many rods should the plant manager expect to manufacture if the order states that all rods must be between 28.9 cm and 29.1 ​cm? nothing ​(Round up to the nearest​ integer.)

Answer 1

so the number of exapectd rods =7888