Answer :
Final answer:
The student's IQ is calculated using the old IQ formula where the mental age is divided by the chronological age, and the result is multiplied by 100. For a 6-year-old with a mental age of 9, the IQ is 150.
Explanation:
The original, or 'old', formula for calculating IQ (Intelligence Quotient) is the ratio of mental age to chronological age, multiplied by 100. In Joe's case, his mental age is 9 and his chronological age (real age) is 6. So, using the old IQ formula we get:
IQ = (Mental Age / Chronological Age) * 100
So, for Joe:
IQ = (9 / 6) * 100 = 150
So, based on the old formula, Joe's IQ would be 150.
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