In anthropometric analysis, which statement correctly describes z-scores?

In anthropometric analysis, which statement correctly describes z-scores?

• A. Raw measurement
• B. Number of standard deviations away from mean
• C. Percentile rank
• D. Ratio

Answer: (B)

Z-scores show how far a value is from the mean in units of standard deviation. They are calculated by subtracting the reference mean from the observed value and dividing by the standard deviation, making different measurements comparable on the same scale. This standardization is why z-scores are useful in anthropometric analysis: you can compare a child’s height, weight, or skinfold relative to a reference group regardless of units or age. They are not raw measurements (which are in cm or kg), not percentile ranks (which describe position within a distribution rather than distance from the mean), and not ratios (which compare two quantities). So the statement that z-scores are the number of standard deviations away from the mean is the best description. For example, a z-score of +2 means the value is two standard deviations above the mean.

Z-scores show how far a value is from the mean in units of standard deviation. They are calculated by subtracting the reference mean from the observed value and dividing by the standard deviation, making different measurements comparable on the same scale. This standardization is why z-scores are useful in anthropometric analysis: you can compare a child’s height, weight, or skinfold relative to a reference group regardless of units or age. They are not raw measurements (which are in cm or kg), not percentile ranks (which describe position within a distribution rather than distance from the mean), and not ratios (which compare two quantities). So the statement that z-scores are the number of standard deviations away from the mean is the best description. For example, a z-score of +2 means the value is two standard deviations above the mean.