Tagged: data

4 guides.

How to find quartiles and the interquartile range, draw a box-and-whisker plot, and spot outliers with the 1.5 × IQR rule.

8 October 2026 · 2 min read

How to find the least-squares line of best fit, what the correlation coefficient r and r² mean, and why correlation is not causation.

8 October 2026 · 2 min read

Find the mean, median, mode and range of a data set step by step, learn which average to use, and see how outliers affect each one.

7 October 2026 · 2 min read

What standard deviation measures, how to calculate it for a population or a sample, why samples divide by n − 1, and a full worked example.

7 October 2026 · 2 min read