OCR Mathematics B (MEI) H640 — LDS9 for June 2027

The accompanying h640-2027-lds9.xlsx is the original OCR workbook, with Information and Data sheets. The source-information text is a readable extraction of Information. This is a sample of 200 people aged 16 or over from the US NHANES 2003–04 survey, not the full survey, a current population or a UK sample. OCR's September 2026 update confirms LDS9 for H640 in 2027. LDS10 applies to H640 from 2028; its earlier use for AS H630 does not change this course's requirement.

The 22 source fields include Sex, Age, Marital, Weight, Height, BMI, ThighLen, UpperArmLength, Waist, Food30, Arm, Pulse, four systolic/diastolic pressure attempts, and average Systolic/Diastolic. Age is in years; Weight in kg; Height, limb lengths and Waist in cm; Pulse counts beats in 60 seconds; pressure is in mmHg. Category names such as marital status are not numerical measurements or ordered ranks. BMI follows mass divided by squared height; use compatible units when calculating it.

The Excel error '#N/A' represents missing data. Do not read it as zero. Filter complete observations for the particular variables being analysed, and state the resulting sample size. Removing every person missing any of the 22 fields would discard observations needlessly. Some diastolic values are zero and OCR notes identify them as erroneous. Keep the original workbook intact; justify any decision to omit these values in a separate working copy.

The attempt columns are labelled 'Disatolic1' to 'Disatolic4' in Data. Retain those source headers when locating columns; their meaning is diastolic pressure. Up to four attempts were permitted to obtain three readings at least one minute apart. The supplied average ignores the first reading unless only one exists, so an unqualified mean of all four attempts would create a different variable. Use the source average or clearly describe an alternative calculation.

Distinguish summaries of the observed sample from claims about a wider population. MEI sample variance uses n−1; establish the actual n after cleaning. An association between measurements does not by itself establish a cause. Spreadsheet investigations should preserve the source, show their filtering/calculation decisions and check graphs and results for plausibility.

The workbook reports download from EEPS on 27 March 2017 and calls the underlying NHANES data public domain. Current series verified against specification version 3.1 (August 2026) and OCR's 3 September 2026 update.
Original release: https://www.ocr.org.uk/Images/717834-large-data-set-9-2027-series-.xlsx
Series update: https://www.ocr.org.uk/administration/support-and-tools/subject-updates/asal-maths-b-lds-763258/
Original workbook SHA-256: dce2b68c668489f2032b34315eeaa1266c4de2a5edf396e81ce3c49e37fd88de