The mass of flour in a bag, W W\,W grams, is normally distributed. It is known that 5% of the bags weigh less than 495 g and 12% of the bags weigh more than 510 g.
Calculate the mean, μ\muμ, and the standard deviation, σ\sigmaσ, of the masses of these bags.
Practise Edexcel A Level Maths Finding the mean and standard deviation with exam-style questions for A Level Maths. 48 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.
