The times it takes students to complete a test are normally distributed with a mean of 58 minutes and a standard deviation of 12 minutes.
Find the time by which 90% of students complete the test.
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.