Scores on a professional certification exam are modeled by a normal distribution.
15% of candidates score lower than 60 marks. 10% of candidates score higher than 85 marks.
Calculate the mean and standard deviation of the scores.
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.
