measure of centrality Flashcards
1
Q
mode
A
value observed the most
2
Q
mean
A
the average
3
Q
median
A
order values low to high then middle number
4
Q
spread
A
how much data values differ from each other
5
Q
when is spread bigger?
A
when the data varies more
6
Q
range
A
max-min
7
Q
quartiles
A
the values that split your data into four equal parts
8
Q
iqr
A
Q3-Q1
9
Q
variance
A
the measure of spread that looks at squared deviation
10
Q
variance (calculate)
A
the average of the squared deviations
sum of squared deviations (calculate the mean > value - mean = deviation
/ number of observations
11
Q
standard deviation (conceptual)
A
the standard deviation is the mean squared deviation in units of the original variable
can never be negative
a larger standard deviation means a lower precision
12
Q
standard deviation (calculate)
A
- calculate the sum of squares
- calculate the variance
- calculate the standard deviation
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