Distances travelled by 100 people are grouped. Using class midpoints gives ∑fx=2651\sum fx=2651∑fx=2651 and ∑fx2=80434.25\sum fx^2=80434.25∑fx2=80434.25. Linear interpolation gives a median of 26.1 miles.
Estimate the mean distance.
Estimate the sample standard deviation.
Compare the mean and median and give a cautious comment about skew.
121 exam-style questions on OCR (MEI) A Level Maths 2.2 Data Presentation and Interpretation, covering 2.2.1 Types of data and standard diagrams, 2.2.2 Area in a histogram is proportional to frequency, 2.2.3 Cumulative frequency diagram, 2.2.4 Describe frequency distributions, 2.2.5 Samples and theoretical distributions, 2.2.6 Interpret a scatter diagram, 2.2.7 Distinct sections and outliers in scatter diagrams, 2.2.8 Correlation and causation, 2.2.9 Select or critique data presentation techniques, 2.2.10 Measures of central tendency, 2.2.11 Simple measures of spread, 2.2.12 Variance and standard deviation, 2.2.13 Outliers, 2.2.14 Cleaning data, and 2.2 Data Presentation and Interpretation. Each one has a worked solution and a mark scheme showing where the marks go.