A new type of fish food has become available for salmon raised on fish farms. Your task is to design an experiment to compare the weight gain of salmon raised over a six-month period on the new and the old type of food. The salmon you will use for this experiment have already been randomly placed in eight large tanks in a room that has a considerable temperature gradient. Specifically, tanks on the north side of the room tend to be much colder than those on the south side. Describe a design for this experiment that takes account of temperature gradient.
1 answer
A randomized block design could be used for this experiment. The eight tanks would be divided into two blocks, with four tanks in each block. The tanks in each block would be randomly assigned to either the new or the old type of food. The two blocks would be placed on opposite sides of the room, with the north block receiving the new food and the south block receiving the old food. This would ensure that the temperature gradient is taken into account, as the tanks in each block would be exposed to the same temperature. At the end of the six-month period, the weight gain of the salmon in each tank would be measured and compared.