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.
328 exam-style questions on WJEC A Level Maths 4.2 Statistical distributions (A-level only), covering 4.2.1 Statistical distributions (A-level only), 4.2.2 Statistical distributions (A-level only), and 4.2.3 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.