The masses of metal components, M M\,M grams, are normally distributed with a standard deviation of 3.2. Given that P(M<12)=0.42P(M < 12) = 0.42P(M<12)=0.42, calculate the mean mass of the components.
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.