Question

Calculate the standard deviation ? of X for the probability distribution. (Round your answer to two decimal places.)

X 0 1 2 3

p(X=x) .2 .1 .6 .1

Answer 1

x                  p                       xp                      x²p

0                 0.2                      0                           0

1                 0.1                       0.1                       0.1

2                  0.6                      1.2                       2.4

3                   0.1                    0.3                         0.9

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Total                                       1.6                        3.4

Mean = = E(X) = 1.6

E(X²) = 3.4

Variance = ² = E(X²) - (E(X))²

                                 = 3.4 - 1.6² = 0.84

So,

StandardDeviation = = = 0.92

So,

Answer is:

0.92