Calculate the range, variance, and standard deviation of these caffeine amounts (mg per 12 oz): 46, 41, 37, 44, 0, 42, 56, 57, 39, 49, 48, 42, 0, 0. Are the stats representative of all cans from these brands?
Barnes \& Noble had science and art books in a 2:5 ratio. After selling 20\% of each, 2,240 books remained. Find initial counts: s= science, a= art. Show your work.