Final answer:
For a 6-year-old child with a mental age of 9, the IQ is calculated using the formula IQ = (Mental Age / Chronological Age) × 100, resulting in an IQ of 150, indicating above-average cognitive abilities.
Step-by-step explanation:
When calculating the Intelligence Quotient (IQ) of a child, a formula is used that takes into account the mental age of the child compared to their chronological age. The formula is IQ = (Mental Age / Chronological Age) × 100. Applying this formula to the scenario where a 6-year-old child has a mental age of 9, we find that the child's IQ is IQ = (9 / 6) × 100 = 150.
This indicates that the child's IQ is significantly above average, reflecting heightened cognitive abilities compared to peers of the same chronological age. It's important to note that while IQ can be a useful tool for measuring cognitive abilities, it is one of many factors that contribute to a child's growth and educational needs.