1. The problem statement, all variables and given/known data If we were to have two normal distributions, say X and Y, which are the scores of students on a test or something, a is the score of a student from X and b is the score of a student from Y, what is the probability that a randomly selected student from X will score more than a randomly selected student from Y, i.ie what's the probability that a>b, or something like a>b+10? Both means and SDs given. Also, if we have a normal distribution, say for weights of bottles of something, and we know that A is the probability that a randomly chosen bottle will weigh less than X, and we then take a sample of say 6 bottles, and we want to find the probability that 2 or less will weigh less than X, is it just 6C0(1-X)^6 + 6C1(X)(1-X)^5 + 6C2(X)^2(1-X)^4 or do I have to standardise again for the population of 6 bottles? Thanks!