Question 1166941: Suppose the average length of stay in a chronic disease hospital of a certain type of patient is 60 days with a standard deviation of 15.if it is reasonable to assume an approximately normal distribution of lengths of stay,find the probability that a randomly selected patient form this group will have a length of stay.
A) less than 48 days
B) greater than 52 days
C) between 40 and 50 days
D) between 30 and 60 days
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! z=(x-mean)/sd
the first is z < -12/15 or z<-0.8 with probability of 0.2119
for the others, z is > -8/15 or probability of 0.7031
between 40 and 50 days, 0.1613
this is z between -1.33 and -0.667
also on calculator 2nd VARS 2normalcdf (40,50,60,15) ENTER
D is 0.4772 probability (between z=-2 and z=0)
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