The mean score is 60 out of 100 and the standard deviation (in other words, the variation in the scores) is 15 marks (see our statistical guides, Measures of Central Tendency and Standard Deviation, for more information about the mean and standard deviation).
What Are the Six Different Types of Swimming Strokes? Swimming provides all-around, low-impact body conditioning as well as exciting competition. Competitive swim meets allow only four strokes -- butterfly, backstroke, breaststroke and the crawl. Two other strokes -- elementary backstroke and sidestroke -- contribute to swimming longer distances, as different sets of muscles are used. The fastest stroke for most swimmers is the front crawl.
Ray-finned fishes (Actinopterygii) are the most diverse of the major groups of fishes, containing more than 25,000 species such as gars, bowfin, eels, salmon, trout, catfish, piranhas, lanternfish, cods, anglerfish, tarpon, basses, cichlids, butterflyfish, wrasses, parrotfish, and many others.