A sample of size 12 is to be taken from a population that is normally distributed with mean 82 and standard deviation 5. Find the probability that the sample mean will be less than 80.
284 exam-style questions on CCEA A Level Maths 4.5 Statistical distributions (A-level only), covering 4.5.1 Statistical distributions (A-level only) and 4.5.2 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.