A variable X X\,X has mean 14 and variance 6.25. The coded variable is Y=X−83Y=\dfrac{X-8}{3}Y=3X−8.
Find the mean and standard deviation of YYY.
A second variable Z Z\,Z has mean 2 and standard deviation 1.2. Compare the location and spread of Y Y\,Y and ZZZ.
121 exam-style questions on OCR A Level Maths 2.2 Data Presentation and Interpretation, covering 2.2.1 Tables and diagrams for single variable data, 2.2.2 Area in a histogram, 2.2.3 Scatter diagrams and regression lines, 2.2.4 Informal interpretation of correlation, 2.2.5 Correlation and causation, 2.2.6 Measures of average and spread, 2.2.7 Calculations of mean and standard deviation, 2.2.8 Outliers, 2.2.9 Selecting or critiquing data presentation, and 2.2.10 Cleaning data. Each one has a worked solution and a mark scheme showing where the marks go.