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.
328 exam-style questions on WJEC A Level Maths 4.2 Statistical distributions (A-level only), covering 4.2.1 Statistical distributions (A-level only), 4.2.2 Statistical distributions (A-level only), and 4.2.3 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.