Biostatistics 1300

Individual- An object described by a set of data (ex. random bird)

Variable- A characteristic about an individual (ex. wingspan, beak length, color)

Population- A group of all individuals of interest (ex. all the students in CPP)

Parameter- A number that describes an aspect of the population (ex. average age of students)

Sample- A subset of the population (ex. all students in STA1300 at CPP)

Statistic- A number that describes an aspect of the sample (ex. average age of students in 1300 Statistic)

Categorical (Qualitative) Variables- Place variable into categories 

Qualitative Nominal Variables- Have no natural order (ex. names, colors, gender, shoe type)

Qualitative Ordinal Variables- Have some sort of natural order (ex. t-shirt size, shoe size, height classification, alphabet

Numeric (Quantitative) Variables- Are variables that are numbers and make sense to do math on

Quantitative Discrete Variables- Are countable and have gaps between possible values (ex. how many languages you speak, number of friends, number of pets)

Quantitative Continuous Variables- Can be any number in a interval (ex. height, weight, earthquake magnitude, length, temperature)

Frequency- A number of times a value appears in a data set

Frequency distribution- Tabulation (make it a table) of the frequencies

Relative frequency- Is the proportion of times a value appears in a data set

Pareto chart- When a bar graph is ordered from most to least frequent

Histograms- Like bar plots for numeric data where the “categories” are called classes or bins

Lower class limit (LCL)- Smallest value that can appear in a class

Upper class limit (UCL)- Largest value that can appear in a class

Class width (CW)- Difference between 2 consecutive LCLs.

Measure of center- Mean, Median

Mean- Add up all values and divide by how many there are

Median- Is the center of a sorted data set 

Standard deviation (SD)- Is the average spread of the data around the mean

Percentile- Is the value such that p% of the data is equal to or less than that value

LOB- Lower outlier bound

UOTs- Upper outlier bound

Outlier- Any number smaller than the LOB or larger than the UOB