Here's the question you clicked on:
xEnOnn
The relative frequency distribution of the weights of all passengers using an elevator is a mound-shaped, with mean 150 and standard deviation 35. Suppose there are n passengers in the elevator, describe and explain the probability distribution of the total weight of n passengers in the elevator.
http://www.scribd.com/doc/53577309/Easy-Statistics-Textbook goto this website!! hope it helps
I am thinking that if n<30, it follows T-Distribution. If n is greater than or equals to 30, it follows Standard Normal. But I am not sure if I am correct. And what assumptions I have to make.
And does CLT even apply in this context?