Statistic question

Question

Assume that adults have IQ scores that are normally distributed with a mean of 98.9 and a standard deviation. Find the first quartile 22.9, which is the IQ score separating the bottom​ 25% from the top​

Answer 1

Are you asking for help in finding the first quartile? It looks like you already know it's 22.9, and what that means. Please clarify your question.

If you are asking how to calculate the first quartile, here's how you do that:

1. order your data from lowest to highest.
2. then find the median. This is the second quartile Q₂.
3. At Q₂ split the ordered data set into two halves.
4. The lower quartile Q₁ is the median of the lower half of the data.
5. The upper quartile Q₃ is the median of the upper half of the data.