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.
Freestyle/Front Crawl Stroke. The most common swimming stroke is the freestyle or front crawl stroke. It is the most natural to perform of all the different swim strokes and can be performed in a swimming pool or other bodies of water. The freestyle stroke allows you to swim straight on your stomach by kicking your legs and rotating your arms over your head.