The concentration of a specific catalyst, C C\,C mg/L, in a chemical reaction follows a normal distribution where C∼N(μ,12.52)C \sim N(\mu, 12.5^2)C∼N(μ,12.52). Observations show that the catalyst concentration exceeds 145.6 mg/L in only 8.85% of trials.
Determine the value of the mean concentration μ\muμ.
Find the probability that the catalyst concentration in a randomly selected trial lies between the mean and 145.6 mg/L.
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.