The Write Right Company manufactures ballpoint pens and has been experiencing a 6% rate of defective pens. Modifications are made to the manufacturing process in an attempt to improve quality. The manager claims that the modified procedure is better because a test of 60 pens shows that only 1 is defective.

a. Assuming that the 6% rate of defects has not changed, find the probability that among 60 pens, exactly 1 is defective.

b. Assuming that the 6% rate of defects has not changed, find the probability that among 60 pens, none are defective.

c. What probability value should be used for determining whether the modified process results in a defect rate that is less than 6%?

d. What can you conclude about the effectiveness of the modified manufacturing process?