Introduction to Biostatistics Flashcards
What is biostatistics?
Branch of statistics that deal with data related to living organisms.
What is a population?
Group that shares one or more common characteristics.
What is a sample?
Representative subset of a population
What is standard deviation referring to?
Distance between the mean and data points.
Gives insight into the spread of the data and is the square root of variance.
What is the interquartile range?
The difference between the 25th and 75th percentile values which can be useful to report with the median.
How can the 25th quartile be calculated?
(n+1)/4
How can the 75th percentile be calculated?
[3(n+1))]/4
What is an outlier?
Anything that is more than 1.5 x IQR
What considerations should be made when plotting data?
Some are clearly better than others.
Some are entirely inappropriate
Some are deliberately misleading
What 3 pieces of information are most important to analyse data?
The shape of the data (distribution)
Location of the data (mean)
Spread of the data (standard deviation)
What information lies between 2 95% chance confidence intervals?
2 standard deviations of the mean
How much of a normal distribution lies between 1 standard deviation of the mean?
68%
How much of a normal distribution lies within 3 standard deviations of the mean?
99.7%
What does the mean and median being equal indicate?
That the distribution is symmetrical
When we calculate the mean of a sample we know that our value is unlikely to be the true mean of the population due to it being an estimate. How is this problem overcome?
It is better to report a range of values rather than a single value.
