There usually is some degree of variability in a sample (golfers do not use only titleist balls; students do not always eat at taco bell). the is a measure of the variability in a sampling distribution.

There are several measure to describe the distribution of some observations. The mean for example give an idea about the average observation. The measure that gives us an idea about variability is the standard deviation; Intuitively it measures how much observations differ from the average.

Maybe haha

Essential for a scientist to do for credibility

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.