Monday, January 1, 2018

Interpolating Statistical Tables

We've all experienced it. You go to use a statistical table - Standard Normal, Student-t, F, Chi Square - and the line that you need simply isn't there in the table. That's to say the table simply isn't detailed enough for our purposes.

One question that always comes up when students are first being introduced to such tables is:
"Do I just interpolate linearly between the nearest entries on either side of the desired value?"
Not that these exact words are used, typically. For instance, a student might ask if they should take the average of the two closest values. How should you respond?