Exercise

# Sum of squares and sum of cross products matrix

Ok, so you have reached the really cool part now ;-)

If you now take your matrix of deviation scores `D`

and multiply it with its transpose, just like prof. Conway did in the video, you get the **matrix of sum of squares and sum of cross products** `S`

. The formula is:

$$\begin{aligned} S_{XX} &= D_{pn}^T D_{np} \end{aligned}$$.

with \(S_{XX}\) the matrix of sum of squares and sum of cross products, \(D_{pn}^T\) the transpose of the deviation matrix, and \(D_{np}\) the n-by-p deviation matrix.

Instructions

**100 XP**