The final graphical tool for assessing the distribution of a set of data is the normal probability plot (i.e., normal quantile plot). ... and “normal” as the sample size increased. Yet, one would ...

When a normal distribution is assumed, one can specify a level of probability (alpha level, level of significance, p) as a criterion for acceptance. In most cases, a 5% value can be assumed.

In a normal distribution, the area under the curve equals one. 68.27% of all data falls within one standard deviation (how dispersed the numbers are) from the mean. 95.45% of all data falls within ...