Standard Error Formula:
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The standard error in regression measures the precision of the estimated regression coefficients. It indicates how much the coefficient estimates vary from the actual population values. A smaller standard error suggests more precise estimates.
The calculator uses the standard error formula:
Where:
Explanation: The numerator represents the standard deviation of residuals, while the denominator accounts for the variability in the independent variable.
Details: Standard error is crucial for constructing confidence intervals and conducting hypothesis tests for regression coefficients. It helps determine the statistical significance of predictors in the regression model.
Tips: Enter comma-separated values for y, y-hat, and x variables. Ensure all arrays have the same number of values. The calculator requires at least 3 data points (n > 2) for valid calculation.
Q1: What's the difference between standard error and standard deviation?
A: Standard deviation measures variability in data, while standard error measures precision of parameter estimates.
Q2: How is standard error used in hypothesis testing?
A: It's used to calculate t-statistics (coefficient/SE) for testing if coefficients are significantly different from zero.
Q3: What does a large standard error indicate?
A: Large standard errors suggest imprecise coefficient estimates, possibly due to small sample size or high variability.
Q4: Can standard error be negative?
A: No, standard error is always non-negative as it's derived from squared quantities.
Q5: How does sample size affect standard error?
A: Standard error decreases as sample size increases, following the inverse square root relationship.