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=80mean=42.6standard deviation=19.3 n = 80 \quad \text{mean} = 42.6 \quad \text{standard deviation} = 19.3 n=80mean=42.6standard deviation=19.3Calculate ∑x \sum x\,∑x and ∑x2 \sum x^2\,∑x2 for these data.
96 exam-style questions on Edexcel A Level Maths Measures of Location and Spread, covering 2.1 Measures of Central Tendency, 2.2 Other Measures of Location, 2.3 Measures of Spread, 2.4 Variance and Standard Deviation, and 2.5 Coding. Each one has a worked solution and a mark scheme showing where the marks go.