Standard Deviation Flashcards
1
Q
What is standard deviation?
A
a measure of the average variation of the data points away from the mean (how spread the data are)
2
Q
What does S stand for?
A
standard deviation
3
Q
What does Σ stand for?
A
sum of
4
Q
What does x stand for?
A
data point
5
Q
What does x̅ stand for?
A
mean
6
Q
What does n stand for?
A
total number of data points
7
Q
step 1 - what do you do first?
A
calculate the mean
8
Q
step 2 - What do you subtract next?
A
subtract the mean from every data point (in the x row)
9
Q
step 3 - What do you square?
A
in the x - xbar row, times the results by themselves
10
Q
step 4 - What do you add up?
A
add up the sum of the squared answers
11
Q
step 5 - What do you divide?
A
divide by n-1
12
Q
step 6 - What do you square root?
A
square root the figure to give the standard deviation
