Hand of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand. The human hand normally has five digits: four fingers plus one thumb; these are often referred to collectively as five fingers, however, whereby the thumb is included as one of the fingers. It has 27 bones, not including the sesamoid bone, the number of which varies between people, 14 of which are the phalanges (proximal, intermediate and distal) of the fingers and thumb. The metacarpal bones connect the fingers and the carpal bones of the wrist. Each human
Normal distribution four categories: Certain quantities in physics are distributed normally, as was first demonstrated by James Clerk Maxwell. Examples of such quantities are: "Approximately" normal distributions occur in many situations, as explained by the central limit theorem. When the outcome is produced by many small effects acting "additively and independently", its distribution will be close to normal. The normal approximation will not be valid if the effects act multiplicatively (instead of additively), or if there is a single external influence that has a considerably larger magnitude than the rest of the effects. There are statistical methods to empirically test that assumption,