1. Suppose that the four inspectors at a film factory are supposed to stamp the expiration date on each
package of film at the end of the assembly line. John, who stamps 20% of the packages, fails to stamp
the expiration date once in every 200 packages; Tom, who stamps 60% of the packages, fails to stamp
the expiration date once in every 100 packages; Jeff, who stamps 15% of the packages, fails to stamp
the expiration date once in every 90 packages; and Pat, who stamps 5% of the packages fails to stamp
the expiration date once in every 200 packages. If a customer complains that her package of film does
not show the expiration date, what is the probability that it was inspected by John?
2. A regional telephone company operate three identical relay stations at different locations. During a
one-year period, the number of malfunctions reported by each station and the causes are shown below:
Suppose that a malfunction was reported and it was found to be caused by human e
or. What is the
probability that it came from station C?