Glossary Coefficient of Variation: the ratio of the standard deviation to the mean. Exclusively breastfed: infant that is fed breastmilk only during the first 4 to 6 months of life. No supplements of water, food, or other drink are provided during this time, however the infant can receive vitamin drops/syrups or medicine. Gestational Age: age of infant calculated from the date of conception. Mean: an average computed by summing the values of observations and dividing by the number of observations. Example: the average of four children's aged 3, 7, 10, 12: 3 + 7 + 10 +12 = 32/4 = 8 Median: representative of the value in the middle. Example: The 50th percentile in a percentile ranking of 1 to 100. Postnatal Age: age of infant calculated from the date of birth. Recumbent length: distance from the crown of the head to the bottom of the feet while the child is lying down. Stature: also referred to as height. Skewness: a measure of the tendency for the distribution of values to be more spread out on one side than the other. Example: Positive skewness indicates that values located to the right of the mean are more spread out than are values located to the left of the mean. Weight-for-stature: the weight of a child at a specific stature regardless of age. Z-score: in a standard normal distribution, the z-score represents the number of standard deviations away from the population mean. In other words, it indicates the degree to which an individual's measurement deviates from what is expected for that individual.