View Full Version : Constructing a probability distribution

11-03-2009, 01:42 AM
I have a difficult probability question that I have no clue where to start from. If there is a way to calculate the answer in this problem using PHstat in Excel, I would prefer that. If not, then I will need to know how to solve it by hand.

Here is my question:

If it rains a person sells umbrellas and earns $65. If it does not rain then the person either washes cars or goes to the race track. The person washes cars on 80% of the days when it does not rain and earns $125 a day. However, $485 a day is lost when the person goes to the race track. If the probability of rain is .2, what is the person's expected (mean) income? (HINT: You will have to construct a probability distribution to answer this question.)

Thank you in advance for whoever helps :-).

11-03-2009, 12:13 PM
.2 (+65) + .64(+125) + .16 (-485)

13+80-77.6 = 15.4

Expected income is $15.4