IQ scores are designed to have a mean of 100 and a standard deviation of 15. IQ testing is one way on which people are categorized as having different levels of metal disability; there are four levels of mental retardation between the IQ scores of 0 and 70.
A. people with Iq scores of 20-35 are said to have severe mental retardation and can learn only basic skills. What percentage of people fall into this range?
B. People with IQ scores of 50-75 have scores in the topmost category of IQ scores that indicate an impairment. THey are said to hve mild mental retardation. They can attain as high as a sixth-grade education and ar often self - sufficient, what percent fall into this range?
C. A person has an IQ score of 66 what is her percentile?
D. A person falls at the 3rd percentle, what is his IQ score? would he be classified as having a mental disability?