The mass of newborn kittens in a specific breed is normally distributed.
20% of the kittens have a mass of less than 85 grams. 12% of the kittens have a mass of more than 115 grams.
Find the mean and standard deviation of the masses.
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.