Frank asked every teacher at his school how long it took them to travel to work. Frank's results are summarised in the summary statistics below.
n=40∑x=900Sxx=1440 n = 40 \quad \sum x = 900 \quad S_{xx} = 1440 n=40∑x=900Sxx=1440Calculate the mean for these data.
Given that σ=Sxxn\displaystyle \sigma=\sqrt{\frac{S_{xx}}{n}}σ=nSxx, calculate the standard deviation 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.