Formulas
ANOVA Chi Square Mean Median Mode Pearson r
Standard Deviation t-test z-score z-test
where N is the number of subjects and x is the score
1. Arrange data numerically
2. Simply take the middle number
Take the number that occurs most often
z-scores and transformed (T) score
Where:
X is the first set of data
Y is the second set of data
(tip: set up a table to better organize sums and squares)
Where: r is calculated Pearson r
Spearman (rho)
Where:
N = number of subjects
D = difference between two ranks for each subject
1 and 6 are constants
(tip: set up a table to calculate the sum of the squared differences easier)
Standard Error of the Mean
Where:
s = standard deviation
n = number of subjects
z- test
Where:
m = mean
µ = population mean
SEm = standard error of the mean
Where:
M = mean
SDM = Standard error of the difference between means
N = number of subjects in group
s = Standard Deviation of group
df = degrees of freedom
t-test of dependent means
Where:
SMD = Standard deviation of the mean difference
D = difference between a pair of means
M = mean
ANOVA - one-factor
(Please see ANOVA for definition of variables and how to calculate)
Where:
O = observed outcome
E = expected outcome
(To calculate E: take the number of subjects and divide by the number of categories)
Where:
O = observed outcome
E = expected outcome
(To calculate E, please refer to Chi-square two way)
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