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%.
Practise Edexcel A Level Maths The Normal Distribution with exam-style questions for A Level Maths. 439 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
