SOLUTION: The average length o stay in a chronic disease hospital for a certain type of patient is 60 days with a standard deviation of 15. It is reasonable to assume an approx. normal dis

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Question 1034332: The average length o stay in a chronic disease hospital for a certain type of patient is 60 days with a standard deviation of 15. It is reasonable to assume an approx. normal distribution of length of stay. Fill in the blanks. The probability is 0.9534 that a patient wlil s tay between _____ and ______days.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Symmetrical function where the missing probability is 1-0.9534=0.0466
Take half of that and get 0.0233.
Now, find the z value that gives a probability of 0.0233.That occurs (use invnorm on calculator) when z=+/-1.99.
z=(x-mu)/sigma
1.99=(x-60)/15
29.85=x-60
x=89.85 or 30.15(30.15 and 89.85 days)
Check is that at 2 SDs the result would be (30,90).