More statistics Flashcards
What is x̄?
x bar = mean
What is ∑x?
sum of data values
What is n?
no. data values
disadvantage mode
doesn’t work if each value only occurs once
advantage median
not affected by extreme values
disadvantage median
only works on quantitative data
advantage mean
truest measure as it takes into account all values
disadvantage mean
affected by extreme values, only works for quantitative data
Random variables
Value depends on the outcome of an event. Usually represented as X.
What is a sample space?
The range of values the random variable can take.
What is a probability distribution?
Description of the probability of each value in the sample space.
What is a probability mass function?
P(X=x) = y, x = sample space
What is the underlying feature associated with each of the bars in a histogram?
area of a bar is proportional to its frequency
Why is a histogram used?
Data is continuous and can be represented in a grouped frequency table
What is the symbol for an empty set?
∅
