# Homework Help: Meaning of fully correlated in statistics

1. Jun 26, 2010

### Gengbinich

Hello!
I was given the following exercise in Statistical Data Analysis:
The method of least squares is often used for straight lines fits
y(x)=mx + c
to data $$(x_i,y_i)$$ Assume all y values have the same (uncorrelated) statistical uncertainty $$\sigma$$ and that they share a common (fully correlated) systematic uncertainty s. How does the covariance matrix look like?

My question is, what do they mean by "fully correlated", and how do I work the "shared common systematic uncertainty s.

Thank you!