AP PSYCHOLOGY

Detailed explanation-1: -An individual’s mental age is then divided by his chronological age and multiplied by 100, yielding an intelligence quotient (IQ). Thus, a subject whose mental and chronological ages are identical has an IQ of 100, or average intelligence.

Detailed explanation-2: -IQ was originally computed by taking the ratio of mental age to chronological (physical) age and multiplying by 100. Thus, if a 10-year-old child had a mental age of 12 (that is, performed on the test at the level of an average 12-year-old), the child was assigned an IQ of 12/10 × 100, or 120.

Detailed explanation-3: -a numerical scale unit derived by dividing an individual’s results in an intelligence test by the average score for other people of the same age. Thus, a 4-year-old child who scored 150 on an IQ test would have a mental age of 6 (the age-appropriate average score is 100; therefore, MA = (150/100) × 4 = 6).

Detailed explanation-4: -The IQ of person is given by the formula, IQ=mc×100, where m is the mental age and c is the chromological age. If 80≤IQ≤140 for a group of 12-year children, find the range of their mental age.