Background: Suppose I have rows of x, y data (SN_C, Value [Sigma Units]) as shown in attached file but also pasted below.
Slope_8 is calculated from the previous 8 [x.y] values.
I want to compare the slope_8 value to the null hypothesis for linear regression (slope =0) and provide a p-value. Is there an easy way to do this?
The formula for the slope 8 was taken from these discussion boards (@txnelson, @Mark_Bailey)and does exactly what I want after I did simple modification to use N=8
If( Row() > 7,
x = J( 8, 1, 1 ) || :SN_C[Index( Row() - 7, Row() )]`;
y = :"Value (Sigma Units)"n[Index( Row() - 7, Row() )]`;
(Inv( x` * x ) * x` * y)[2];
)
I know I should know how to do this and my apologies for being too stupid to figure it out. Its been 30 years since I've taken matrix algebra 
