30 people ran a race and their race times, xxx, were recorded.
For these people ∑x=480∑x2=7800\sum x = 480 \quad \sum x^2 = 7800∑x=480∑x2=7800
Calculate the mean and 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.