Sample Statistics. 1  x refers to a sample mean. 2  s refers to the standard deviation of a sample. 3  s2 refers to the variance of a sample. 4  p refers to the proportion of sample elements that have a particular attribute. 5  q refers to the proportion of sample elements that do not have a particular attribute, so q = 1 - p.
Ecology/Environmental Response. The most basic interest of ecologists is how organisms interact with their environment. Inanimate objects do not normally interactâthey are simply acted upon by forces in the environment. Organisms, however, cannot be totally passive within a chain of events and still sustain life.
Living things respond to their environment. Response to stimuli is an important characteristic of life. Anything that causes a living organism to react is called a stimulus (plural is stimuli) Stimuli can be external or internal. For instance, if you feel like going to the bathroom, it is an internal stimulus that is controlled by the brain.