Question: A steel pipe casting firm has purchased steel parts from a supplier for several years and has found that 10% of the parts must be returned because they are defective. An order of 10 parts is received.

a.) What is the probability that three or fewer of these parts are defective?

b.) What is the mean and standard deviation for the number of defective parts in orders of 10?

c.) What is the probability of receiving between 1 and 4 defective parts?