Having a problem with a question in stat class. Here it goes: a lab reports the mean of three(3) weighings. The mean is 123mg and the standard deviation is 0.08mg? What is the distribution of this mean? And what is the probability that the lab reports a weight of 124mg or higher? Any help would be greatly appreciated.

The distribution of the mean is approximately normal, with mean approximated by XBAR = 123, and standard deviation approximated by SD/SQUAREROOT(n) = .08/SQUAREROOT(3).

Given the above, it is then a customary normal distribution problem to calculate the probability of X>=124 from a normal with parameters 123 and .08/SQUAREROOT(3).