# Biostatistics

## Descriptive Statistics

Descriptive Statistics is the part of Statistics in charge of representing, analysing and summarizing the information contained in the sample. After the sampling process, this is the next step in every statistical study and usually consists of:

## Regression

In the last chapter we saw how to describe the distribution of a single variable in a sample. However, in most cases, studies require to describe several variables that are often related.

## Probability

Descriptive Statistics provides methods to describe the variables measured in the sample and their relations, but it does not allow to draw any conclusion about the population. Now it is time to take the leap from the sample to the population and the bridge for that is Probability Theory.

## Discrete Random Variables

Random variables The process of drawing a sample randomly is a random experiment and any variable measured in the sample is a random variable because the values taken by the variable in the individuals of the sample are a matter of chance.

## Continuous Random Variables

Probability distribution of a continuous random variable Continuous random variables, unlike discrete random variables, can take any value in a real interval. Thus the range of a continuous random variables is infinite and uncountable.

## Physiotherapy exam 2022-06-06

Degrees: Physiotherapy Date: June 6, 2022 Question 1 The patients of a physiotherapy clinic were asked to assess their satisfaction in a scale from 0 to 10. The assessments are summarized in the table below.

## Physiotherapy exam 2022-05-06

Degrees: Physiotherapy Date: May 6, 2022 Question 1 A basketball player scores 12 points per game on average. What is the probability that the player scores more than 4 points in a quarter?

## Physiotherapy exam 2022-03-11

Degrees: Physiotherapy Date: March 11, 2022 Question 1 The table below shows the number of credits obtained by the students of the first year of the physiotherapy grade. $$48, 52, 60, 60, 24, 48, 48, 36, 39, 54, 54, 60, 12, 46$$

## Pharmacy exam 2022-01-17

Degrees: Pharmacy, Biotechnology Date: January 17, 2022 Question 1 A diagnostic test for a disease with a prevalence of 10% has a positive predictive value of 40% and negative predictive value of 95%.

## Pharmacy exam 2021-11-22

Degrees: Pharmacy, Biotechnology Date: November 22, 2021 Question 1 The cranial capacity (in dm$^3$) of a primate population follows a normal probability distribution $X\sim N(\mu,\sigma)$. The chart below shows the Gauss bell of $X$.