SOLUTION: A population of values has a normal distribution with μ=219.7 and σ=53.7. You intend to draw a random sample of size n=14. Find the probability that a single randomly selected

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Question 1168050: A population of values has a normal distribution with μ=219.7 and σ=53.7. You intend to draw a random sample of size n=14.
Find the probability that a single randomly selected value is greater than 248.4.
P(X > 248.4) = Incorrect
Find the probability that a sample of size n=14 is randomly selected with a mean greater than 248.4.
P(¯¯¯X > 248.4) =
Enter your answers as numbers accurate to 4 decimal places.

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z=(x-mean)/sd
>(248.4-219.7)/53.7 or >28.7/53.7, which is 0.534
this has probability of 0.2965
-
this has sd of 53.7/sqrt(14)=14.35
so the above will be z>28.7/14.35 which is 2
that probability is 0.0228
Much less likely for the mean of a sample to be as far from the mean of the population as a single value.