Answer:
The Idea of I.Q goes to Lewis Terman .He graded points to persons after performing few tests. He Categorised them as:
1. x ≥140 →[Genius]
2. 120≤x<140→[Above Excellent]
3. 110≤x<120→[Excellent]
4. 90≤x<110 →[ Average Excellence]
5. 80≤ x<90→[Dull ]
6.70≤x<80→[Little bit of Deficiency]
7. x<70→[Less or Maximum chances of Deficiency]
We will draw normal distribution curve for the following data.
1.90<50% of I.Q<110
2. 85<70% of I.Q<115
3. 70<95% of I.Q<130
4.60<99.5% of I.Q<140
So , The answer is,About 95% of the population have I.Q scores that are within ___30__ points above or below 100.