The time taken to assemble a specific furniture kit is normally distributed with a mean of 140 minutes140\text{ minutes}140 minutes and a standard deviation of 25 minutes25\text{ minutes}25 minutes.
Find the time by which 95% of customers complete the assembly.
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.