KNOWLEDGEBASE - ARTICLE #1950

# Bug: Y intercept as specified X value doesn't work with Deming regression.

Last modified October 3, 2014

This bug is in Prism 6 and probably earlier, fixed in 6.06 and 6.0g.

To see the bug:

- Enter XY data.
- Choose Deming regression.
- Ask Prism to report the Y intercept at a specified value of X (not 0.0).

What happens: Prism reports the Y intercept at X=0.0, not at the specified X value. The confidence interval for the Y intercept is centered on the intercept at X=0.0 so is not correct (although the width of the confidence interval is correct, it is centered in the wrong place). So the two highlighted values are wrong when you ask for the intercept at a X value other than 0.0. The default (Y intercept when X=0.0 works fine).