descriptive statistics Flashcards
what are the 3 types of measures of Central Tendancy
mean, mode, meduim
how to work out the mean
add all scores up and divide by the amount of scores totally together
how to work out the mode
the most frequent occurring score that appears more than once
how to work out the medium (middle)
the middle value once data is sorted
what are the 2 types of measure of dispersion
range, standard deviation
how to work out the range
subtract the highest score by the lowest score
how to work out standard deviation
how far scores are by the mean
square root of the variances calculates the SD
use of bar charts
- used for discrete data
- shows data being divided into categories
- if bars do not touch meaning that they are dealing with separate conditions
use of histograms
- bars are touched together
- represents we are dealing with continuous data
use of line graphs
points are connected by lines showing the change in values
use of scattergrams
- shows associations between co-variables
2 types of distributions
normal and skewed
what are normal distributions
symmetrical patterns of frequency data that forms a bell shapes pattern
what are skewed distributions
a spread of frequency data that is not symmetrical, instead the data is all clustered to one end
2 types of skewed distributions
positive and negative skews
what are positive skews
most of the distribution is correlated on the right side
what are negative skews
most of the distributions of data is correlated on the left side
calculate percentages
number of participants x 100, then divide by the total of number of participants
increased percentages
- the increase between the 2 number being compared must be calculated
- this should be divided by the original figure then multiplied by 100
