Biostatistics Flashcards
What do we usually want to know?
Something about a population
How do we find out something about a population?
We take a sample to make as testing the whole population is unrealistic
What kind of sample do we take?
A random sample as it makes it representative of the population and allows inferences to be made about the population
When can uncertainty occur?
If there is and error in the sample estimate, the sample size isn’t effective and if varied answers are obtained upon repeats
When does the sample distribution become narrower?
When the sample size gets larger and there is less variation therefore more certainty
How do we get a sample distribution?
Take a sample from the population many times, calculate the mean each time and then place it on a graph. The sample distribution centre should be close to the actual centre
What is categorical data?
There are only a few certain options available
What is continuous data?
When there is a measurable range of options
How is categorical data presented?
Data is presented as percentages or portions
What do we want to find out about continuous data?
Where the centre (central tendency) is and how spread out the data is
What does the standard deviation measure?
The variability/spread in the data
What does the standard deviation tell us?
How far away from the mean each observation/average is
