SOLUTION: Please help I keep trying and end up with .25 but this is incorrext Given normal distributed population mean of 100 and variance 100 sample of 25 P find P(100<Xbar<105) and

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Question 1091592: Please help I keep trying and end up with .25 but this is incorrext
Given normal distributed population mean of 100 and variance 100 sample of 25 P
find P(100 and
P(Xbar>96)

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
The probability of the mean's being exactly 100 is 0, because this is a continuous function and the probability at any given point is 0. This is the answer for a continuous function; for a discrete function, it would be able to be calculated.
Probability x bar>96
z>(96-100)/10/sqrt(25), the 10 is the sd, the sqrt (variance).
z>-4*5/10
z>-2
0.9772
It has to be greater than 0.5, because the population mean is 100, so any sample of 25 will tend towards that mean of 100. To be greater than 96 would be even more so.