Independent T-test

Formulas

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Mean

where N is the number of subjects and x is the score

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Median
1. Arrange data numerically
2. Simply take the middle number

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Mode
Take the number that occurs most often

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Standard Deviation

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z-scores and transformed (T) score

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Pearson r

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)

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Coefficient of Determination

Where: r is calculated Pearson r

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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)

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Standard Error of the Mean


Where:
s = standard deviation
n = number of subjects

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z- test

Where:
m = mean
µ = population mean
SEm = standard error of the mean

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t-test of independent means

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