The heights of a specific species of plant are normally distributed. 20% of the plants are shorter than 15 cm. 10% of the plants are taller than 25 cm.
Find the mean and standard deviation of the heights of the plants.
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.