Almost all of the students' scores are below the average. Therefore, in this case the mean is not a good representative of the central tendency of this sample. The median, on the other hand, is the value which is such that half the scores are above it and half the scores below. So in this example, the median is 8. There are four scores below and four above the value 8. So 8 represents the mid point or the central tendency of the sample.
Definition of duct. 1 : a bodily tube or vessel especially when carrying the secretion of a gland. 2a : a pipe, tube, or channel that conveys a substanceb : a pipe or tubular runway for carrying an electric power line, telephone cables, or other conductors.
2. a hollow or concave utensil, as a cup, bowl, or pitcher, used for holding liquids or other contents. 3. a tube or duct, as an artery or vein, conveying blood or some other body fluid. 4. a water-conducting duct within the xylem of vascular plants, composed of connected cells without intervening partitions. 5. a person regarded as a holder or receiver of a particular trait or quality: a vessel of grace.