The scores of students in a physics olympiad, SSS, follow a normal distribution. Data shows that 10% of students scored less than 45 marks, and 5% of students scored more than 85 marks.
Calculate the mean score and the standard deviation of the scores.
48 exam-style questions on Edexcel A Level Maths 3.5 Finding the mean and standard deviation. Each one has a worked solution and a mark scheme showing where the marks go.