The battery lives, x x\,x hours, of 40 rechargeable batteries were measured.
For these batteries ∑x=760∑x2=14960\sum x = 760 \quad \sum x^2 = 14960∑x=760∑x2=14960
Calculate the mean and the standard deviation for these data.
32 exam-style questions on Edexcel AS 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.