Adam asked every teacher at his school how long it took them to travel to work. Adam's results are summarised in the summary statistics below.
n=84∑x=3581∑x2=184 092 n = 84 \quad \sum x = 3581 \quad \sum x^2 = 184\,092 n=84∑x=3581∑x2=184092Calculate 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.