stats. plz help i have exams in two days!
posted by shasha on .
find the indicated prob.:
the amount of snowfall falling in a certain mountain range is normally distributed with a mean of 86 inches, and a standard deviation of 12 inches. what is the probability that the mean annual snowfall during 36 randomly picked years will exceeds 88.8 inches?

0.0808

how did u come up with it?thanks

Z = (mean1  mean2)/standard error (SE) of difference between means
SEdiff = √(SEmean1^2 + SEmean2^2)
SEm = SD/√(n1)
Since only one SD is provided, you can use just that to determine SEdiff.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score.