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.
Human swimming typically consists of repeating a specific body motion or swimming stroke to propel that body forward. There are many kinds of strokes, each defining a different swimming style or crawl.Most strokes involve rhythmic and coordinated movements of all major body parts â torso, arms, legs, hands, feet, and head. Breathing typically must be synchronized with the strokes, too.It is possible however to swim by moving only legs without arms or only arms without legs; such strokes may be used for special purposes, for training or exercise, or by amputees (paralympians) and paralytics.reathing typically must be synchronized with the strokes, too. It is possible however to swim by moving only legs without arms or only arms without legs; such strokes may be used for special purposes, for training or exercise, or by amputees (paralympians) and paralytics.