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.
228 exam-style questions on CCEA A Level Maths 4.5.1 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.