By convention, specific symbols represent certain sample statistics. For example, 1  x refers to a sample mean. 2  s refers to the standard deviation of a sample. 3  s 2 refers to the variance of a sample. 4  p refers to the proportion of sample elements that have a particular attribute.or example, 1  P refers to a population proportion; and p, to a sample proportion. 2  X refers to a set of population elements; and x, to a set of sample elements. 3  N refers to population size; and n, to sample size.
The brain is one of the most important organs in the body and gives humans the capacity for language, art, and rational thought. A brain surgeon, or neurosurgeon, is a doctor that performs surgery on the nervous system, particularly the brain. He or she will also treat a wide range of problems affecting the central nervous system is the job of a brain surgeon.
NEUROSURGEONS. What is neurosurgery? Neurological surgery is the medical specialty concerned with the diagnosis and treatment of patients with injury to or diseases of, the brain, spine or peripheral nerves. A neurological surgeon (neurosurgeon) may provide either surgical or non-surgical care depending on the nature of the injury or illness. What kinds of illnesses do neurological surgeons treat? Neurosurgeons are more than just brain surgeons.