Can someone please remind how to calculate (1) significance (eg rule of thumb based on effect vs error) and (2) the predictive formula for a 2^3 full factorial? I recall how to calculate the main and interactive effects…need formulas/method for determning 1 and 2 above.

Again, I want to do this by hand for a simple 2^3 full factorial. No MTB.

Please help....



I didn't find the right solution from the Internet.
References
https://www.isixsigma.com/topic/doe-calculations/

demo video