SOLUTION: The random variable X has the probability distribution shown at right Find the standard deviation of X x │ P(X=x) 1 │ 0.45 3 │0.10 5 │ 0.45

Question 1186284: The random variable X has the probability distribution shown at right
Find the standard deviation of X
x │ P(X=x)
1 │ 0.45
3 │0.10
5 │ 0.45
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
E(X)=mean = x*p(x) all summed
this is 0.45+0.30+2.25, multiplying the 3 rows. They add to 3, the mean, which can be seen also by the symmetry of the distribution.
sd is sqrt sum of (square differences)(probability)/n
=4*0.45+0*0.10+4*0.45
=3.60
sqrt (3.60)=1.90

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