I'm using Excel 2003 under XP Professional to examine the relationship, if
any, between two sets of data - let's call them 'audit score' and 'profit'.
I have 74 data points for each set. When I graph the data points in an XY
scatterplot and then add a trendline to the data series, I get a slope for
the line of .033. However, when I use the correlation function in data
analysis, I get a .0185.

I thought these two numbers should be the same. Although the difference is
not very large, the difference gets noticeable when I look at certain subsets
of the data; on one subset, the numbers come out identical to the fourth
decimal place.

Any thoughts?