x’ forecast only on HP-32E

[Namir]

Projecting x onto y' (or y-hat) is not the whole picture! The value for y-hat is the mean of a range defined by a confidence interval. So x is related to yhat residing in a confidence interval. In order words x is related to a set of y values! This is the more complete picture. Calculating x-hat from y (or should I say y-hat) does not give x-hat residing in an x-oriented confidence interval.

This is what I learned from my 1979 stat course teacher. He had a PhD in chemical engineering from MIT and was an HP-65 calculator toting teacher! He enjoyed seeing my HP-67 and was pleased to learn that I had learned statistics from the HP calculators stat pacs!

Namir