The lifespan, T T\,T hours, of a certain component is normally distributed. Given that P(T<800)=0.3P(T < 800) = 0.3P(T<800)=0.3 and P(T>1200)=0.15P(T > 1200) = 0.15P(T>1200)=0.15.
Find the mean and standard deviation of the lifespan of the component.
48 exam-style questions on Edexcel A Level Maths 3.5 Finding the mean and standard deviation. Each one has a worked solution and a mark scheme showing where the marks go.