A museum recorded the time, in minutes, taken by all 80 visitors on a guided tour. The summary values are n=80n=80n=80, ∑x=1960\sum x=1960∑x=1960 and Sxx=∑(x−xˉ)2=6480S_{xx}=\sum (x-\bar{x})^2=6480Sxx=∑(x−xˉ)2=6480, where n n\,n is the number of visitors, ∑x \sum x\,∑x is the total time, and SxxS_{xx}Sxx is the sum of squared deviations from the mean.
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.