[NW] You Explain It! Percentiles Explain the meaning of the following percentiles. Source: Advance Data from Vital and Health Statistics. a. The 15th percentile of the head circumference of males 3 to 5 months of age is 41.0 cm. b. The 90th percentile of the waist circumference of females 2 years of age is 52.7 cm. c, Anthropometry involves the measurement of the human body. One goal of these measurements is to assess how body measurements may be changing over time. The following table represents the standing height of males aged 20 years or older for various age groups. Based on the percentile measurements of the different age groups, what might you conclude?

Verified step by step guidance

1. Step 1: Understand the meaning of a percentile. The pth percentile is the value below which p% of the data falls. For example, the 15th percentile means 15% of the measurements are below that value.
2. Step 2: For part (a), interpret the 15th percentile of head circumference for males aged 3 to 5 months as the value below which 15% of the head circumference measurements fall, which is 41.0 cm.
3. Step 3: For part (b), interpret the 90th percentile of waist circumference for females aged 2 years as the value below which 90% of the waist circumference measurements fall, which is 52.7 cm.
4. Step 4: For part (c), analyze the table showing standing height percentiles for males aged 20 years or older across different age groups. Observe how the percentile values change as age increases, noting any trends such as decreases in height percentiles with increasing age.
5. Step 5: Conclude that the data suggests a trend where standing height tends to decrease with age among males 20 years and older, as seen by the gradual decline in percentile values from the 20–29 age group to the 80 or older group.

Key Concepts

Percentiles

Percentiles indicate the relative standing of a value within a data set by showing the percentage of data points below that value. For example, the 15th percentile means 15% of the data falls below that measurement. Percentiles help interpret individual measurements in the context of a population.

Anthropometric Measurements

Anthropometry involves measuring physical dimensions of the human body, such as height, head circumference, and waist circumference. These measurements are used to assess growth, health, and changes over time in populations, providing important data for medical and nutritional studies.

Interpreting Percentile Tables Over Age Groups

Percentile tables across age groups show how measurements like height vary with age. Observing trends in percentiles helps identify patterns such as growth, decline, or stability. For example, a decrease in height percentiles with increasing age may indicate age-related height loss in the population.