Hypothesis Test Formula:
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The hypothesis test for two samples compares two sample statistics to determine if there is a statistically significant difference between them. The test statistic is calculated by dividing the difference between the two statistics by the standard error of the difference.
The calculator uses the following formula:
Where:
Explanation: The test statistic measures how many standard errors the difference between the two statistics falls from zero. Larger absolute values indicate stronger evidence against the null hypothesis.
Details: Hypothesis testing is fundamental in statistical analysis to determine whether observed differences between groups are likely due to chance or represent true differences in the populations.
Tips: Enter the two sample statistics and their standard error. The standard error must be non-zero. The units should be consistent across all inputs.
Q1: What does the test statistic value mean?
A: The test statistic indicates how many standard errors the difference between statistics is from zero. Values further from zero (typically >2 or <-2) suggest statistical significance.
Q2: How do I interpret a significant result?
A: A significant result suggests there is evidence to reject the null hypothesis of no difference between the two statistics.
Q3: What's the difference between one-tailed and two-tailed tests?
A: One-tailed tests check for a difference in one direction only, while two-tailed tests check for any difference (either direction). This calculator provides the test statistic which can be used for either.
Q4: What if my standard error is zero?
A: A zero standard error suggests no variability in your difference estimate, which is unusual. Check your calculations or data.
Q5: Can I use this for proportions or means?
A: Yes, this general formula applies to differences between means, proportions, or other statistics, as long as you use the appropriate standard error.