A random sample of size nnn is taken from a population that is normally distributed with mean 252525 and standard deviation 444. Find the minimum sample size such that the probability of the sample mean being greater than 27.527.527.5 is less than 1%1\%1%.
79 exam-style questions on Edexcel A Level Maths 3.1 The Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.