T-Statistic Formula:
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The t-statistic is a measure used in hypothesis testing to determine if there is a significant difference between the means of two groups. It follows a t-distribution under the null hypothesis of no difference between group means.
The calculator uses the t-statistic formula:
Where:
Explanation: The formula calculates how many standard errors the difference between means is from zero, providing a standardized measure of the difference between groups.
Details: The t-statistic is crucial for determining statistical significance in comparing two sample means, particularly in research studies, A/B testing, and quality control applications.
Tips: Enter the means, standard deviations, and sample sizes for both groups. Standard deviations must be positive values, and sample sizes must be integers greater than zero.
Q1: When should I use this t-statistic formula?
A: Use this formula when comparing means from two independent groups with potentially unequal variances (Welch's t-test).
Q2: What is a typical range for t-statistic values?
A: There's no fixed range, but typically values beyond ±2.0 may indicate statistical significance, depending on degrees of freedom and chosen alpha level.
Q3: How do I interpret the t-statistic value?
A: Compare the calculated t-value to critical values from the t-distribution table based on your degrees of freedom and significance level to determine statistical significance.
Q4: What are the assumptions for this test?
A: The test assumes that both samples are randomly selected, observations are independent, and the sampling distribution of the difference between means is approximately normal.
Q5: Can this calculator handle one-sample t-tests?
A: No, this calculator is specifically designed for two-sample t-tests. For one-sample tests, a different formula would be required.