SOLUTION: The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience. Ad

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Question 1036954: The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience.


Admissions Probability
1,060 0.5
1,400 0.1
1,620 0.4




1.
What is the expected number of admissions for the fall semester?


Expected number of admissions


Compute the variance and the standard deviation of the number of admissions. (Round your standard deviation to 2 decimal places.)



Variance
Standard deviation

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
E(X) = 1,060*0.5 + 1,400* 0.1 + 1,620* 0.4 = 1,318, the expected number of admissions for the fall semester.
E%28X%5E2%29+=+1060%5E2%2A0.5+%2B+1400%5E2%2A+0.1+%2B+1620%5E2%2A+0.4+=+1807560
==> Var%28X%29+=+E%28X%5E2%29+-+%28E%28X%29%29%5E2+=+1807560+-+1737124+=+70436
=> SD%28X%29+=+sqrt%28Var%28X%29%29+=+sqrt%2870436%29+=+265.40, to two decimal places (the zero at the hundredth place is significant.)