what is a-ta$ what is ata what is the importance of aa$ in statistics which part of the matrix represents the principal components of the data? why is the data matrix important why is it important to use eigenvectors in a matrix? what is the role of the matrix ata what is the purpose of eigenvector in the matrix? why is $ata important in math why is data matrix $ata$ so important what is ata in statistics why is ta$ significant what is the purpose of the math matrix, $atta? what is a atta what role does the asterisk represent in an average linear equation what is the importance of $ata$ in statistics what is $ata in statistics why is data analysis important definition and function of eigenvector what is a-ta used for