Basic Statistics II (4) - End E1 Flashcards
What are measures of central tendency?
describe the typical or central value in a distribution
- mean, median, mode
What are measures of dispersion?
describe the spread of data
- range, standard deviation, variance
What is standard deviation?
measures the amount of variation or dispersion from the average
What does a high standard deviation mean?
indicates that the data points are spread out over a large range of values
What does a low standard deviation mean?
the data points tend to be very close to the mean (also called expected value)
What is variance?
directly related to standard deviation
the square of it - sigma squared
Would this have a high or low variance?
low
What is categorical data?
nominal
ordinal
What is numerical data?
interval
ratio
What is nominal data?
refers to categorically discrete data such as name
part of categorical data
What is ordinal data?
data that has a discrete ranking
ex. freshman, sophomore, etc
order like ordinal
type of categorical data
What is interval data?
numerical data that is measured along a scale
each point is at equal distance from one another
type of numerical data
T/F: Intervals can have negative values 0 is arbitrary
TRUE
What is ratio data?
interval data with a natural data point
type of numerical data
What is required in ratio data?
NO negative numbers
0 is a true zero