Frequency distributions Flashcards
What are three ways to present descriptive statistcs
graph presentation, in numbers (table formats), or in verbal descriptions (writen report)
How do you know which graph to use for which type of data set?
Arrange according to level of data
What type of variables are nominal/categorical and ordinal data sets classed as
Discrete variables
interval and ratio level data are called (variable type)
Continuous variables
What type of graph is used for categorical or nominal data?
Bar chart - in this type of chart, tallest bar is the most frequent observation, if there are two sets of data compared, you can’t deduct meaningful differences from it unless you perform inferential test.
Continuous data is most often displayed as
frequency histograms, you first create a frequency table then histogram, on histogram, you can see where lowest and highest values are, and where they tend to cluster
if you have a very large data set what can you do
group the data, so the shape of distribution of our histogram will be clearer
what is uni modal distribution
When there is one clear peak
Bi modal distribution is
When there are to clear peaks, they do not have to be of the same height
If the distribution has a long tail to the right, this is called
Positively skewed data
Negatively skewed data meaning..
Long tail to the left of the distribution
What two adjectives can yo use in regard to the shape of distribution
It can be symmetrical or skewed (positively , or negatively)
When displaying frequency data on a graph, what is the best one to use for categorical data?
Bar chart
Best type of frequency graph for numerical data
frequency histogram
