Confidence Interval Calculator
Compute confidence interval for a sample mean.
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What This Calculator Does
Compute confidence interval for a sample mean.
It combines Sample Mean, Sample SD, Sample Size, Z Value to estimate Confidence Interval, Margin of Error.
Formula & Method
Core equations: Known \sigma: CI=\bar{x}\pm z_{\alpha/2}\frac{\sigma}{\sqrt n}; unknown \sigma: use t.
Notation used in the formulas: R = Confidence Interval; x_{1} = Sample Mean; x_{2} = Sample SD; x_{3} = Sample Size; x_{4} = Z Value.
Method summary: inputs are normalized to consistent units, core equations are evaluated, then secondary values are derived and rounded for display.
Use this calculator for quick scenario analysis. Start with baseline values, change one driver at a time, and compare how sensitive the results are to each input shown above.
Inputs Used
- Sample Mean: Used directly in the calculation.
- Sample SD: Used directly in the calculation.
- Sample Size: Used directly in the calculation.
- Z Value: Used directly in the calculation.
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