Bar plot and histogram. We review the differences between bar plots, useful for representing qualitative variables, and histograms, for quantitative ones.
Confidence interval and sample size. The characteristics of the standard error of a proportion allow us to make with confidence precise inferences without the need of very large samples.
Conditional probability. Sometimes the initial probability can change if we have certain information. This is what is called conditional probability.
Combinatory and probability. An example of the use of combinatory is presented to obtain the possible and total events to calculate the probability of that event.
Theoretical quantiles graph. The theoretical quantiles graph (q-q plot), used to check the normality of the data of a distribution, is reviewed.