RF & CRF Example: A Canadian generic pharmaceutical manufacturer sells 78 different products. The distribution of the annual sales amounts last year for these products is shown below. Answer: RF= FUN and CFR= accumulation starting from first number N = 78 F = 17 Social Recommedations Example: Those who arrived at the link from a recommendation had a correct recall of 62.07% as compared to those who arrived at the link from browsing who had a correct recall of 62.91%. Since the difference in percentage is relatively small, one can conclude that social recommendations have very little impact on correct recall