One Sample T-Statistic Formula:
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The one sample t-statistic measures how many standard errors the sample mean is from the hypothesized population mean. It's used in hypothesis testing to determine if a sample comes from a population with a specific mean.
The calculator uses the one sample t-statistic formula:
Where:
Explanation: The numerator measures how far the sample mean is from the hypothesized mean, while the denominator (standard error) scales this difference by the sample size.
Details: The t-statistic is crucial for conducting t-tests, which help determine if observed differences between sample and population means are statistically significant or due to random chance.
Tips: Enter the sample mean, hypothesized mean, sample standard deviation (must be ≥0), and sample size (must be ≥1). All values must be valid numbers.
Q1: When should I use a one sample t-test?
A: When you want to compare a sample mean to a known or hypothesized population mean, especially when the population standard deviation is unknown and sample size is small (typically n < 30).
Q2: What does the t-statistic value mean?
A: Larger absolute values indicate greater deviation from the hypothesized mean. The sign indicates direction (positive = sample mean > hypothesized mean).
Q3: How is this different from a z-test?
A: t-tests are used when population standard deviation is unknown (using sample SD instead) and with small samples. They have heavier tails than the normal distribution used in z-tests.
Q4: What are the assumptions of this test?
A: The data should be approximately normally distributed, observations should be independent, and the sample should be randomly selected.
Q5: How do I interpret the t-statistic?
A: Compare it to critical values from the t-distribution (with n-1 degrees of freedom) to determine statistical significance at your chosen alpha level.