Example 8.5.1---Classifying into k normals

xx1={191,185,200,173,171,160,188,186,174,163};
xx2={131,134,137,127,128,118,134,129,131,115};
xx3={ 53, 50, 52, 50, 49, 47, 54, 51, 52, 47};
yy1={186,211,201,242,184,211,217,223,208,199};
yy2={107,122,144,131,108,118,122,127,125,124};
yy3={ 49, 49, 47, 54, 43, 51, 49, 51, 50, 46};
zz1={158,146,151,122,138,132,131,135,125,130};
zz2={141,119,130,113,121,115,127,123,119,120};
zz3={58,51,51,45,53,49,51,50,51,48};