A museum recorded the time, in minutes, taken by all 80 visitors on a guided tour. The results are summarised below, where n n\,n is the number of visitors, ∑x \sum x\,∑x is the total time, and Sxx=∑(x−xˉ)2S_{xx}=\sum (x-\bar{x})^2Sxx=∑(x−xˉ)2.
Calculate the mean and the population 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.