Hemoglobin helps the red blood cells transport oxygen and remove carbon dioxide. Researchers at NASA wanted to discover the effects of space flight on a rat's hemoglobin. The following data represent the hemoglobin (in grams per deciliter) at lift-off minus 3 days (H-L3) and immediately upon return (H-R0) for 12 randomly selected rats sent to space on the Spacelab Sciences 1 flight. Is the median hemoglobin level at lift-off minus 3 days less than the median hemoglobin level upon return? Use the α = 0.05 level of significance.