Caffeine content in a 5-ounce cup of brewed coffee ranges from 60 to 180 mg, depending on brew time, coffee bean type, and grind. (a) use the midrange to estimate the measure of centre. midrange 120 (b) use the empirical rule to estimate the standard deviation. standard deviation 20 (c) why is the assumption of a normal, bell-shaped distribution important in making these estimates