HP 48G Linear Regression Best Fit Line

[MNH]

(12-23-2021 04:13 AM)Rodger Rosenbaum Wrote:  The HP48 and descendants come through again! I'm glad it all worked out--you'll be the envy of the other guys you work with. :-)

My next step is to get a direction on the best fit line. I've been scanning the Internet for this. It looks like I'll need to know where the x and y-intercepts are in order to get a delta x and a delta y. I can then use tan^-1(delta x / delta y) to calculate the azimuth of the line.

I have a question unrelated to the above. What does the data on stack level 3 mean? The data is placed on the stack after selecting right-shift, STAT, Fit data..., Linear Fit.

3: '672.34932+0.00832...
2: Correlation: 0.893...
1: Covariance:
94.09017

What's the purpose of the single quotation mark to the left of the first digit on stack level 3? If you view (right-shift, STACK) the data appears as 672.34932+0.00832X.