This video explains you about formulae and it's derivation of mean, mode and median in individual, discrete and continuous series and standard deviation and mean deviation.
for the proper interpretation of scientific data generated in the biomedical sciences. In these sciences, subjects (patients, mice, cells, etc.) exhibit considerable variation in their response to stimuli. This variation may be due to different treatments or it may be due to chance, measurement error, or underlying characteristics of the individual subjects. Biostatistics is particularly concerned with disentangling these different sources of variation, as well as seeking to distinguish between correlation and causation, and making valid inferences from known samples. (For example, when patients are treated with two different therapies, do the results justify the conclusion that one treatment is better than the other?)