Trace metals in drinking water affect the flavor and an unusually high concentration can pose a health hazard. we obtain the following data for 9 glasses of water. each glass contained the same amount of water. we look at the zinc concentration (mg/l) in bottom water and the zinc concentration in surface water for each glass. it is fine to round any standard deviations to 2 decimals. glass 1 2 3 4 5 6 7 8 9 bottom water .48 .32 .62 .58 .76 .77 .70 .64 .52 surface water .42 .24 .39 .41 .61 .61 .63 .52 .41