Mathematics Statistical Terms Flashcards
Mode
- Most common or most reoccurring number in a data set.
- The mode is the item that occurs the most often in a data set
Mean
- Sum of values divided by number of values.
- The mean is the most commonly used average
- To calculate the mean of a set of values, we add together the values and divide by the total number of values
Median
- Middle value
- The median is the middle number when all numbers are in order
Range
- Largest value minus the smallest value
- The lowest score subtracted from the highest score is called the range
- If the scores are spread out, then the range will be higher, and the scores less consistent
- If the scores are close together than the range will be lower and the scores more consistent
Outliers
Very unusual results are called outliers
Skewed data
- Data that is heavily weighted towards one end of the data set is said to be skewed
- When data is skewed, the mode is not an appropriate value
Interquartile range
- The interquartile range is the range of the middle half of the data
- Interquartile range = upper quartile - lower quartile
Lower Quartile
The lower quartile is the data value that is a quarter of the way along the list
Upper Quartile
The upper quartile is the data value that is three quarters of the way along the list
Categorical data
Non-numerical using labels of categories
Numerical data
Numerical using numbers
Types of categorical data
- Nominal
- Ordinal
Types of numerical data
- Discrete
- Continuous
Continuous data
- It can take on any value in an interval
- “Measured”
Discrete data
- It can only have specific values
- “Counted”
Nominal data
- Don’t provide sequence
- Example: Eye colour
Ordinal data
- Provide sequence
- Example: Letter grades
Population
Every entity that is related to the investigation
Sample
A part of that population
Survey
Representative data collected from a portion of the population or sample
Census
Data collected from an entire population
Experimental
Data collected by measuring or counting or assigning labels
Random selection
Ensures all elements of a population have an equal chance of being selected
Stratified selection
Ensures that groups within a population have a similar representation within a sample
