. Q. 1. I have itendified an application of the summation sign, ∑, within a mathematical formula but I don’t really understand what it means. Can you point me to a suitable reference?

A. When learning about statistical procedures, you may come acrss the summation sign. For example, this sign crops up in the formula for calculating the chi-square statistic in a chi-square test of assoication. You can learn more about what this sign means at The summation sign – how to interpret it .

. Q. 2. I am a little rusty on rounding and would like to present my findings to 3 d.p. Could you point me to a suitable reference with a relevant rule of thumb?

A. Yes; you should find the information at the site Rounding to Decimal Places very useful.

 

 

Basic notation and rounding by Margaret MacDougall is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.