Collecting informations. Qualitative and quantitative variables. Frequency distributions. Graphical representations. Mode, median, mean, quantiles. Range, variance, standard deviation. Covariance, correlation. Events, probability, axioms. Bayes theorem. Random variables: Bernoulli, Binomial, Normal. Simple random sampling. Sampling distribution of mean and proportion. Estimation. Confidence interval. Hypothesis testing for a mean, a proportion, two means and two proportions.