30 people ran a race and their race times, xxx, were recorded.
For these people ∑x=466∑x2=7592\sum x = 466 \quad \sum x^2 = 7592∑x=466∑x2=7592
Calculate the mean and the standard deviation for these data.
244 exam-style questions on AQA A Level Maths 2.2 L: Data presentation and interpretation, covering 2.2.1 Single-variable data diagrams, 2.2.2 Scatter diagrams and correlation, 2.2.3 Central tendency, variation and standard deviation, 2.2.4 Outliers and cleaning data, and 2.2 L: Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.