* We can calculate a minimum sample size.

* We can summary data with tables or graphics.

* We can use measures of central tendency and dispersion, to summary the data.

* In a random sample of children between 6-12 years we obtained a 27% of prevalence of amebiasis; with methods of inferential statistics, we know that the prevalence in the population is between 22 and 34%.

* Considering gestational age with the birth weight, with a regression model we can say that if the gestational age is higher, the birth weight is higher, too.