Definition
Biostatistics applies statistical methods to biological and health data — summarizing measurements, spotting patterns, and predicting future outcomes from current data, widely used in public health (e.g. tracking disease spread, testing whether a treatment works).
Mean
Median: the middle value of data arranged in order (average of the two middle values if the count is even).
Mode: the value that occurs most often (a data set can have no mode, one, or several).
Example 1 — mean, median, mode together
Find the mean, median and mode of .
- Mean .
- Already ordered, values (odd) — median is the th value: .
- and each appear twice — two modes.
Answer: mean , median , modes and
Remember
Mean uses every value and is pulled toward outliers; median only cares about the middle position, so it resists them — for very skewed biological data (e.g. a few extreme measurements), median is often the more representative choice.
Definition
A bar chart displays categories on one axis and the height/length of each bar shows that category's frequency or value on the other — used to compare groups visually, e.g. the number of different blood types in a sample.
Quick Recap
- ●Biostatistics: statistics applied to biological/health data, used heavily in public health
- ●Mean sum count; median middle value (ordered data); mode most frequent value(s)
- ●Mean is affected by outliers; median resists them
- ●Bar chart: categories on one axis, bar height/length shows frequency or value
