. A nine year old boy is 120 cm tall. If the present height of the boy is 75% of his full height, calculate the full height which the boy will eventually reach at the end of growth period.

To calculate the boy's eventual full height, we need to determine what 100% would be if 120 cm represents 75%. Using basic proportion: if 75% = 120 cm, then 1% = 120 ÷ 75 = 1.6 cm. Therefore, 100% = 1.6 × 100 = 160 cm. Alternatively, you can use the formula: Full height = (Current height ÷ Current percentage) × 100 = (120 ÷ 75) × 100 = 160 cm.

This calculation suggests the boy will reach approximately 160 cm (or 5 feet 3 inches) at full adult height. However, it's important to note that this is a mathematical exercise rather than a precise medical prediction. Actual adult height depends on multiple factors including genetics (parental heights), nutrition, overall health, timing of puberty, and environmental factors. Growth spurts during adolescence can vary significantly between individuals, and some boys continue growing into their late teens or even early twenties. Pediatricians use more sophisticated growth charts and percentile curves to track development and predict adult height more accurately.