The weights of bags of sugar are normally distributed with a mean of 505 g and 12% of the bags have a weight of less than 498 g.
Find the standard deviation of the weights of the bags of sugar.
147 exam-style questions on OCR A Level Maths 2.4.6 Probabilities using the normal distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.