The normal probability plot is a graphical technique for normality testing. Used to assess data set follows normal distribution.
Poisson distribution is a discrete probability distribution; it describes the mean number of events occurring in a fixed time interval.
The chi square (χ2) distribution is the best method to test a population variance against a known or assumed value of the population variance
Data distributions is a function that specifies all possible values for a variable and also quantifies the relative frequency.
Central tendency is the idea that when using normal data, all three of the main measures (mean, mode, median) tend to be roughly the same.