Question 5

When a particular machine is functioning properly, 75% of the items produced are non-defective.

1. If eight items are examined, what is the probability that one is defective?
2. If eight items are examined, what is the probability that exactly three are non-defective?
3. If eight items are examined, what is the probability that at least 6 are non-defective?

Question 6

The average starting salary of this year's graduates of a large university (LU) is $55,000 with a standard deviation of $4,000. Furthermore, it is known that the starting salaries are normally distributed.

1. What is the probability that a randomly selected LU graduate will have a starting salary of at least $52,700?
2. Individuals with starting salaries of less than $45,00 receive a free class. What percentage of the graduates will receive the free class?
3. What percent of graduates will have their salaries one standard deviation from the mean?
4. What is the range of salaries that are one standard deviation from the mean?