Answer:
a frequency distribution is an overview of all different values in some variable and the number of times they occur that is frequency distribution tells how frequencies are distributed over values frequency distributions are mostly used for summarizing categorical variables.
in non probability sampling the sample is selected based on the random criteria and not every member of the population has a chance of being included, non probability sampling methods include convenience sampling voluntary response sampling purposive sampling snowball sampling and quota sampling.
in statistics a central tendency (or measure of central tendency) is a central or typical value for a probability distribution. ... Colloquially measures of central tendency are often called averages the term central tendency dates from the late 1920s