The arithmetic mean is the most common measure of central tendency. It is calculated by summing all individual data points in a set and dividing that sum by the total count of those points. It provides a representative average value for the entire distribution, though it can be sensitive to extreme outliers.

The ordinal scale is a level of measurement where data is categorized and ranked. While the order of the values is significant, the exact differences between the values are not necessarily known or equal. Examples include rankings in a race or Likert scale survey responses.

The mean is the arithmetic average of a data set. Because it is calculated using the sum of all values, it possesses unique mathematical properties that allow it to be used in complex algebraic operations, unlike the median or mode.

The provided answer 'Over Pronator' is technically contradictory to the question description, as over-pronation involves excessive inward rolling of the foot. A runner with minimal rolling is typically described as a 'supinator' or 'under-pronator'. This answer is preserved as per instructions despite the potential terminology conflict.

The four-site skinfold method is a common anthropometric protocol used to estimate body density and body fat percentage. By measuring subcutaneous fat at specific anatomical landmarks—typically the biceps, triceps, subscapular, and suprailiac regions—practitioners can apply standardized equations to calculate total body composition. While other protocols exist using more sites, the four-site method remains a standard practice in many fitness assessment settings.

Chronological age is the standard measure of time elapsed since an individual's birth. It is expressed in years, months, and days. This metric is essential in physical education and developmental studies to categorize individuals into appropriate age groups for training, competition, and growth assessment, distinguishing it from biological or psychological age markers.

The stadiometer is the standard medical and anthropometric instrument used to measure human height accurately. It consists of a vertical ruler and a sliding headpiece that ensures the measurement is taken at the crown of the head while the subject maintains proper posture. Other tools like the ammeter measure electricity, while the dynamometer measures force, making them unsuitable for height measurement.

To convert weight from pounds (lbs) to kilograms (kg), one must multiply the weight in pounds by the conversion factor of approximately 0.453592. Calculating 160 multiplied by 0.453592 results in approximately 72.57 kilograms. When rounded to the nearest whole number, this value is 73 kilograms, which aligns with the provided option.

William Sheldon's somatotype theory categorizes human physique into three primary types: Endomorph (round and soft), Mesomorph (muscular and athletic), and Ectomorph (lean and fragile). 'Osomorph' is not a recognized term within this psychological and physiological classification system. The theory was intended to link body types to temperament, though it has faced significant scientific criticism over the decades.

Dual-Energy X-ray Absorptiometry (DXA) is a highly accurate, non-invasive medical imaging technique. It is considered the gold standard for measuring body composition, as it provides precise data on bone mineral density, fat mass, and lean muscle mass distribution throughout the body.