Math 1431 – Spring 2003 – Test #1 – Practice
Question 5 Answer
  1. 65.5 percent of people aged 20 to 34 have IQ scores above 100. (Use NDAREA program).
  2. IQ scores below 93.1 fall in the lowest 25% of the distribution. (Use invNorm function of calculator with area = 0.25).
  3. IQ scores above 159 are needed to be in the highest 2.5%. (Use invNorm function of calculator with area = 1 – 0.025 = 0.975. Remember that the invNorm uses the area to the left of a point so to find the area to the right subtract from 1.).