I need to calculate the mean(+/-SD) final value of a variable from the mean(+/-SD) baseline value and the mean(+/-SD) change from baseline. So, for example:
- Mean baseline weight is 40(+/-2) kg.
- Mean change from baseline is +5(+/-1) kg.
I'd assume the correct final mean is 45kg, but how would I go about calculating a new SD?
I've googled for methods of calculating 'Pooled SD', but those only seem to apply to pooling same variables (like weights from different groups) and I don't think those apply here. This question seems the most similar to my question but also seems to try the exact opposite of what I'm trying to achieve.