A machine produces metal rods whose lengths, LLL, follow a normal distribution. It is found that 15% of the rods have a length less than 15.2 cm and 10% of the rods have a length greater than 16.5 cm.
Find the mean and standard deviation of the rod lengths.
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.