# This data frame has 20 rows and 2 columns. Data comes from an experiment to # test the paper brightness depending on a shift operator. # # Determine whether there are any differences between the operators. What is the # nature of these differences? "bright" "operator" "1" 59.8 "a" "2" 60 "a" "3" 60.8 "a" "4" 60.8 "a" "5" 59.8 "a" "6" 59.8 "b" "7" 60.2 "b" "8" 60.4 "b" "9" 59.9 "b" "10" 60 "b" "11" 60.7 "c" "12" 60.7 "c" "13" 60.5 "c" "14" 60.9 "c" "15" 60.3 "c" "16" 61 "d" "17" 60.8 "d" "18" 60.6 "d" "19" 60.5 "d" "20" 60.5 "d"