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• Unpaired (independent) t test
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• Chi-squared test

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Tables

• Critical values (chi-square )
• Critical values (t test)

Selected Critical Values of the Chi-Squared Distribution

If the calculated chi-squared statistic exceeds a tabled value for the appropriate number of degrees of freedom, then observed values are significantly different from expected values at the confidence level indicated by p.

For one degree of freedom:
p=0.05, 3.84; p=0.025, 5.02; p=0.01, 6.64; p=0.005, 7.88

For two degrees of freedom:
p=0.05, 5.99; p=0.025, 7.38; p=0.01, 9.21; p=0.005, 10.6

For three degrees of freedom:

p=0.05, 7.82; p=0.025, 9.35; p=0.01, 11.34; p=0.005, 12.84

For four degrees of freedom:

p=0.05, 9.49; p=0.025, 11.14; p=0.01, 13.28; p=0.005, 14.86

For five degrees of freedom:

p=0.05, 11.07; p=0.025, 12.83; p=0.01, 15.09; p=0.005, 16.75