Statistics

Stat

Discrete Data

Data that can be counted

Continuous Data

Data that can be measured

Different types of averages

Mean, Median, Mode

Mean

Average of a set of numbers

How to calculate Mean

Add all values together and divide by number of values

Mode

Most common number in a set of values

Range

Highest number minus lowest number

Sigma sign

The sum of

Line of best fit

A straight line that best represents the data on a scatter plot

Standard Deviation

Average distance any given point is away from the mean

Large Standard Deviation:

Points aren’t close to mean

Small Standard Deviation:

Points are close to the mean

Variability

How spread out data is

When can you use SD?

Symmetrical Data

Outlier

Data point that doesn’t fit the general trend of data

What is any point considered if it isn’t in the first three levels of SD?

Outlier

Histogram

For continuous data

Bar Chart

For discrete data

Quartiles

Divide data equally into four groups each worth 25%

IQR (interquartile range)

Q3 - Q1

Cumulative Frequency

Sum of all frequencies up to a particular value

Systematic Sampling

Sampling Method where elements are selected at regular intervals from a sorted list

Convenience Sampling

Non-probability sampling method where samples are selected based on easy availability and proximity to researcher

Random Sampling

Type of probability sampling in which the researcher randomly selects a subset of participants from a population

Quota Sampling

Non-probability sampling method that relies on the non-random selection of a predetermined number or proportion of units, exclusive groups

Stratified Sampling

Type of sampling method in which the total population is divided into smaller groups or strata to complete the sampling process