Trout Hemoglobin Study

The data in the following table show the measurements of hemoglobin (grams per 100 ml) in the blood of brown trout. The trout were placed at random in four different troughs. The fish food added to the troughs contained, respectively, 0, 5, 10, and 15 grams of sulfamerazine per 100 pounds of fish (coded T1, T2, T3, and T4). The measurements were made on ten randomly selected fish from each trough after 35 days.