The upper quartile of a set of data is a number that

Question

what is a set of data for any numbers

Answer 1

The upper quartile - also known as the third quartile and the 75th percentile - is the point that divides the top quarter and bottom three quarters of a distribution.  So, if your IQ score is at that point, you did better than three quarters (75%) of the norming sample.

If your data are presented in a box and whisker plot, the upper quartile is the right edge of the box.