Sentence:  For example , on the basis of the regression equation , a child with an <WSD>I.</WSD> Q. of 120 in this sample would be expected to earn an achievement test score of 4.8 ( grade equivalent ) . 
Meaning of the word marked with <WSD> tags:  a measure of a person's intelligence as indicated by an intelligence test; the ratio of a person's mental age to their chronological age (multiplied by 100)