T-Value Formula:
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The t-distribution is a probability distribution used in statistics for estimating population parameters when the sample size is small and/or when the population standard deviation is unknown. It is similar to the normal distribution but has heavier tails.
The calculator uses the t-value formula:
Where:
Explanation: The t-value measures how many standard errors the sample mean is from the population mean.
Details: The t-value is crucial for hypothesis testing (t-tests) and constructing confidence intervals, especially with small sample sizes where the normal distribution isn't appropriate.
Tips: Enter all required values in consistent units. The sample size must be at least 2, and standard deviation must be positive.
Q1: When should I use the t-distribution instead of normal distribution?
A: Use the t-distribution when sample sizes are small (typically <30) or when the population standard deviation is unknown.
Q2: What are degrees of freedom in t-distribution?
A: Degrees of freedom (df) = sample size - 1. It affects the shape of the t-distribution.
Q3: How is the probability calculated?
A: The probability is calculated using the cumulative distribution function (CDF) of the t-distribution with appropriate degrees of freedom.
Q4: What does a high t-value indicate?
A: A high absolute t-value suggests the sample mean is significantly different from the population mean.
Q5: Can this be used for paired or two-sample t-tests?
A: This calculator is for one-sample t-tests. Different formulas are needed for paired or two-sample tests.