Originally Posted by

**ANDS!** Just simple multiplication. 3 times the expectation that he will have to get it repaired in one year.

0.6

Do you know how to do linear transformations of means, std, variance, etc.? That's all you are doing here. Multiplying by a scalar 3. However the effect that is has on the mean (just multiply by three), is not the same as it has on the std and variance.

So would it be ".55*3=1.65. My calculations rest on the assumption that the standard deviation is the same every year. This assumption is not reasonable." ?

If the printer fails, is that going to affect the computer failing?

I don't understand what you're saying...

should I add the costs (100+120) and std. deviations (13.68+30)???

Yes you do. You already calculate the EXPECTED cost of one, and they give you the EXPECTED cost of the other.