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| Question 1081995:  Please help me solve the following probability question
 The average length of stay in a hospital is useful for planning purposes. Suppose that the following is the distribution of the length of stay in a hospital after a minor operation.
 x =  1,   2,   3,    4,    5
 P(x) =  0.6, 0.1, 0.04, 0.02, c
 Find the variance and standard deviation
 Answer by Boreal(15235)
      (Show Source): 
You can put this solution on YOUR website! E(X)=0.6+0.2+0.12+0.08+1.2; the 1.2 comes from5*0.24, which is what c has to be to have the probability =1 E(X)=2.2
 V(X)= sum (x-E(X))^2*p(x)
 -(1.2)^2*0.6=0.864
 -(0.2)^2*0.1=0.004
 0.8^2*0.04=0.0256
 1.8^2*0.02=0.0648
 2.8^2*0.24=2.0256
 Adds to 2.984
 SD=1.73, sqrt of the variance
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