Plotting Multiple linear regression line on one graph

[#1]

Hi There!

I have 10 Y measurements all against one X, how do I compare the responses on one graph using the linear regression lines (on the scatterplots)? The Y are in triplicates.  I have attached the Excel file with the data.

[#2]

I ran some real world data through Matlab & the method in this thread. The agreement is to more than the significant digits in the data. Thanks so much. This is excellent and so easy to use.

[#3]

The parameter estimates table shows no intercept offset for polymer[C] but the prediction equation implies it is actually -39.05458586. Why is that please?

[#4]

The parameter estimates do not show the parameter estimate for the last category of a categorical variable due to the way the coding of that variable is done. That last category is -1*(sum of the other parameter estimates). In the example, 50.9 + -11.9 = 39.0 (with rounding, of course). Therefore, mathematically, you do not need to display the last parameter estimate (in actuality, it is not displayed because of the way the mathematics are done).

Anyhow, this is why JMP offers the Prediction Equation option. You can also see it in the Expanded Parameter Estimates table, available from the red popup menu choosing Estimates > Expanded Estimates.