Answer :
William Stern's formula for the intelligence quotient was mental age/chronological age × 100. What is the IQ of a 12-year-old with a mental age of 9?
c. 75
The IQ of a 12-year-old with a mental age of 9 is calculated using the formula IQ = (mental age / chronological age) imes 100, which yields an IQ score of 75.
The question asks about the calculation of the intelligence quotient (IQ) of a 12-year-old with a mental age of 9 using William Stern's formula. The formula for calculating IQ is IQ = (mental age ÷ chronological age) imes 100.
Using the provided data, we can substitute the values into the formula: IQ = (9 ÷ 12) imes 100 = 0.75 imes 100 = 75. Therefore, the IQ of a 12-year-old with a mental age of 9 would be 75.
