One LDS9 record has the following blood-pressure readings, in mm Hg.
Reading123Systolic192192180Diastolic000\begin{array}{c|ccc}\text{Reading}&1&2&3\\\hline\text{Systolic}&192&192&180\\\text{Diastolic}&0&0&0\end{array}ReadingSystolicDiastolic119202192031800
The stored average values are 186 mm Hg for systolic pressure and 0 mm Hg for diastolic pressure.
Verify the stored average systolic pressure.
Identify the value that should be investigated during data cleaning.
Explain why replacing this value immediately by the sample mean would not be justified.
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.