A contractor is interested in the total cost of a project on which he intends to bid. He knows that his costs will be $600 per day (for labour), plus a fixed cost of $15,000 (for materials, etc.). The contractor forms subjective probability assessments of the number of days,Y, that will be required to complete the project as shown below:

Y

1

2

3

4

5

p(y)

0.1

0.3

0.3

0.2

0.1

1. [2]Find the expected number of days needed to complete the project,Y.
2. [2]Find the variance of the completion time,Y.
3. [3]What is the expected value of the total cost of the project?
4. [3]What is the standard deviation of the total cost?