The masses of a particular variety of apple are normally distributed with a mean of 180 g. It is found that 15% of the apples have a mass greater than 200 g.
Find the standard deviation of the masses of these apples.
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Markscheme
3.5 Finding the mean and standard deviation Questions
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.