Ten hens whose eggs recently hatched were selected at random. From each of these hens, two chicks were selected to test the effect of a vitamin supplement on early growth. The chicks in each pair were...

Ten hens whose eggs recently hatched were selected at random. From each of these hens, two chicks were selected to test the effect of a vitamin supplement on early growth. The chicks in each pair were siblings of similar high birth weight. One chick in each pair was given the supplement and the other was not. After two weeks the weight of each chick was recorded. The researcher would like to test the research hypothesis that the supplement increases growth rate of chicks in the first weeks after hatching against the null hypothesis that it has no effect. The most appropriate test would be...