A sample of 10 packs of a brand of chewing gum was taken. Each pack was weighed and their weights, in grams, are shown. 43 point 0 , 43 point 7 , 49 point 6 , 46 point 9 , 47 point 6 , 45 point 4 , 51 point 2 , 48 point 0 , 40 point 5 , 49 point 1 What is the z -score for the pack of gum weighing 43 grams?