Consumer Reports Health (www.consumer reports.org/health) reported the accompanying caffeine concentration (mg/cup) for 12 brands of coffee:

Coffee Brand Caffeine concentration

(mg/cup)

Eight O’Clock 140 Caribou 195 Kickapoo 155 Starbucks 115 Bucks Country Coffee Co. 195 Archer Farms 180 Gloria Jean’s Coffees 110 Chock Full o’Nuts 110 Peet’s Coffee 130 Maxwell House 55 Folgers 60 Millstone 60 Compute the values of the quartiles and the interquartile range for this data set.