# Financial Calculator HP 10bII - Standard Deviation with Probability

I have a financial calculator and am trying to use it to calculate the standard deviation when probability is involved.

For a standard deviation question say on the numbers 1, 5, 6, 10

Press 1, E+
Press 5, E+
Press 6, E+
Press 10, E+
Press Stat Button - ox


However I have just been presented with a question in the format

Probability | Score
--------------------
0.1         | 1
0.3         | 5
0.4         | 6
0.2         | 10


With the forumla (sorry I don't know math format, feel free to edit)

stdev^2 = Sum of (Probability * (Score - Average Score))^2

How would I do this on my calculator?

Many thanks,

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