227.212 Biostatistics Lab 2

Introduction

In this lab we’ll

• Use RMarkdown notebooks for some analyses, like we did last week, but writing a bit more.
• Do some exploratory data analysis on ‘How to weigh a Moroccan donkey’.
• Look at what we expect by chance for a proportion or mean, by sampling from a known population.

Exercise 1: Exploratory analysis of donkey data

This exercise is concerned with data on 386 Donkeys used to transport goods to market in Morocco. We’ll look at how the body weight and other variables are distributed.

1. Start by downloading the first lab file by Right clicking and Save File As… here:

   https://www.massey.ac.nz/~jcmarsha/227212/lab2_donkeys.Rmd

2. Load RStudio up, and use the File->Open File… option, browse to where you saved it, and load it up.

3. Work through this file to explore the donkey weight data.

Exercise 2: The sampling distribution

In this exercise we’ll explore how the sampling process affects estimates of population measures - i.e. how different samples produce different estimates, and how those differences can be characterised by an uncertainty distribution.

1. Start by downloading the second lab file by Right clicking and Save File As… here:

   https://www.massey.ac.nz/~jcmarsha/227212/lab2_sampling.Rmd

2. Use the File->Open File… option, browse to where you saved it, and load it up.

3. Work through this file - we’ll mostly just be running code in this one, seeing what happens, and making notes.