# T-test: ratios or log ratios

### #1

Posted 30 April 2012 - 07:03 AM

### #2

Posted 30 April 2012 - 09:29 AM

One must presume that long and short arguments contribute to the same end. - Epicurus

...except casandra's that belong to the funniest, most interesting and imaginative (or over-imaginative?) ones, I suppose.

That is....if she posts at all.

### #3

Posted 01 May 2012 - 07:53 AM

### #4

Posted 01 May 2012 - 08:19 AM

Anyway the before-after treatments are paired data and I'd test them either separately using raw data with a paired t-test or using ratios with the ratio paired t-test as offered by some software (e.g. graphpad, prism). The normal student's t-test I would not use for ratio data as they're not normal distributed. If not possible to use the ratio test, use the non-parametric alternative the Mann-Whitney U Test...

One must presume that long and short arguments contribute to the same end. - Epicurus

...except casandra's that belong to the funniest, most interesting and imaginative (or over-imaginative?) ones, I suppose.

That is....if she posts at all.

### #5

Posted 02 May 2012 - 01:18 AM

btw, sorry for the misunderstanding. non-native speaker's here