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