Z scores are the number of standard deviations a score or a value (x) away from the mean and are a measure of the dispersion of data.
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
The Normal distribution is used to analyze data when there is an equally likely chance of being above or below the mean for continuous data.