What is Covariance?
I have no idea how many times to search "What is Covariance?" in Google... Here hope one simple page easily summarizes Covariance. Variance X Name Math score English score Smith 78 80 Alice 90 55 Lee 45 92 George 65 85 Ben 83 76 mean 72.2 77.6 X-E[X] Smith 5.8 2.4 ->(times) 13.92 Alice 17.8 -22.6 -> -402.28 Lee -27.2 14.4 -> -391.68 George -7.2 7.4 -> -53.28 Ben 10.8 -1.6 -> -17.28 COV= -170.12 Covariance value is -170.12