Exercise 5.4 A lot of 75 washers contains 5 defectives whose variability in thickness is unacceptably large. A sample of 10 washers is selected at random without replacement. 1. Determine the...

Extracted text: Exercise 5.4 A lot of 75 washers contains 5 defectives whose variability in thickness is unacceptably large. A sample of 10 washers is selected at random without replacement. 1. Determine the probability mass function of the number of defective washers (X) in the sample. 2. Find the probability that at least one unacceptable washer is in the sample. 3. Calculate the mean and variance of X.