Im having an issue with solving problems such as these in under 5min…has anyone any suggestion or perhaps some shortcuts on the BA II Plus to solve these?

At this point, any response is much appreciated.

Joe Mayer, CFA, projects that XYZ Company’s return on equity varies with the state of the economy in the following way:

State of Economy Probability of Occurrence Company Returns Good .20 20% Normal .50 15% Poor .30 10%

The standard deviation of XYZ’s expected return on equity is closest to:

25 sec with the DATA and STAT functions on the TI BA II Plus Pro (those should be the same as on the ti ba II plus). I agree with cpk123 that it doesn’t hurt to do it manually though!!!

Make sure to enter the probabilities as full values (10 instead of 0.1) in order to avoid the ERROR 4 in 1-V Mode.

Here is a good tutorial on the Statistical part of the TI BA II Plus:

Note: If you’re calculating the SAMPLE standard deviation with weighted probability, you can’t use the calculator. The reasoning is because you could enter 20, 50 and 30 for Y1, Y2, Y3, respectively or 200, 500, 300 for Y1, Y2, Y3, respectively. Therefore, your “n” is different.