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. Find the mean and standard deviation of the following probability distribution:

x 1 2 3
P(x) 0.4 0.25 0.35


Please show all of your work.

  • stats -

    To find the mean:
    SUM [x * P(x)]

    Multiply each x by its respective probability P(x). Add together for a total. This will be your mean.

    To find variance:
    SUM [x^2 * P(x)] - mean^2

    Square each x. Multiply each squared x by its respective probability P(x). Add together for a total. Square the mean. Subtract the squared mean from the total. This will be your variance.

    To find standard deviation:
    Take the square root of the variance.

    Hopefully, this information will help you with problems of this type.

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