1. In everyday language, the term correlation means about the same thing as relationship
   or association. In statistics, the more technical meaning
   of the word refers to
   O a. the ratio of two variances.
   O b. the standardized difference between two variables.
   Oc. the percentage of variability shared between two variables.
   O d.
   a measure of the direction and strength of a relationship between two
   variables.