Comparison Of Means Formula:
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The Comparison Of Means test (t-test) is a statistical method used to determine whether there is a significant difference between the means of two groups. It calculates a t-value which can be compared against critical values to assess statistical significance.
The calculator uses the following formula:
Where:
Explanation: The t-value represents the difference between means relative to the variability in the data. Larger absolute t-values indicate more significant differences.
Details: The t-value is crucial for hypothesis testing in research, allowing researchers to determine if observed differences between groups are statistically significant or likely due to chance.
Tips: Enter the means for both groups and the standard error of their difference. All values must be valid (SE_diff > 0).
Q1: What is a good t-value?
A: The significance depends on degrees of freedom, but generally absolute values > 1.96 indicate significance at p < 0.05.
Q2: How is SE_diff calculated?
A: SE_diff is typically calculated as sqrt[(s1²/n1) + (s2²/n2)] where s are standard deviations and n are sample sizes.
Q3: When should I use this test?
A: Use when comparing means of two independent groups with normally distributed data and similar variances.
Q4: What are the assumptions?
A: Assumes independence, normality, and homogeneity of variance between groups.
Q5: How does this differ from ANOVA?
A: t-test compares exactly two means, while ANOVA can compare multiple means simultaneously.