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.
616 exam-style questions on Edexcel A Level Maths The Normal Distribution, covering 3.1 The Normal Distribution, 3.2 Finding Probabilities for Normal Distributions, 3.3 The Inverse Normal Distribution Function, 3.4 The Standard Normal Distribution, 3.5 Finding the mean and standard deviation, 3.6 Approximating a Binomial Distribution, and 3.7 Hypothesis Testing with the Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.