I have a simple regression with 24-36 months of data, let's say of Sales which is the dependant variable and % spend on promotions in that month as independent variable (amongst other variables). I am running a normal linear regression on this

The independent variable , let's say can vary from 0-100% and the Dependant variable Sales varies from 7-10K $.

After running the regression, i am getting unusually high beta for the Predictor, 50-60K as the value.

What i want to understand is, is this the right construct of running a linear regression and if any transformation is required? I dont think so, as when i plotted the two on a scatter plot and fit a linear trend like,it fit perfectly and while displaying the R-squared, it showed a value of 60%.

if i want to understand, what is the impact on Sales on a 1% increase in the INdependent variable - how do i do this?

Currently, what i am doing is :

1. Computing Y (Baseline) as (beta * Average X + C)

in my case Beta is 60K, Average X is, let's say 15% and hence i obtain Y (Baseline) as 8.5k

2. For a 1% increase in X, i want to compute Y... so, i keep beta as same, C as same, i add 1% to average X and hence compute Y

i subtract this Y from Y(Baseline) computed in Step #1.

Is there anything i am doing wrong...?

Thanks! ]]>

What I want is a confidence envelope around the model estimates of Z.

Thanks, ]]>

just looking at doing some simple linear regression and I've got views on an article. Occasionally we choose to spend a bit of money to promote the article and boost views. I want to see how spending affects our views.

It's pretty simple, but since spending is so on and off i'm not sure. I get a good R-squared value when I include those days but a terrible one when I don't. How I see it is including days of no spend gives a good R-squared because spending definitely boosts our views. Not including those days has a terrible R-squared because the amount we're spending isn't hugely affecting the views we're getting.

If I'm looking to do simple linear regression, should I include those days where we haven't spend any money? If I do include those days, how do I choose which days to include? Do I pick days in between spending? Would I pick days before/after spending has started/ended?

Cheers guys! ]]>