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Student's t and chi-square, on CI
Simulates samples for 'CI', confidence intervals (μ, σ).
2024.Jul.03 19:22:17
n ≥ 4 Sample size. •
μ, σ (both) [X] Gaussian distribution mean and standard deviation. •
prob % Confidence level. •
trials, seed N. of simulation trials and RNG seed. •
tol, npoints Tolerance for numerical inversion, and graph points. •
Show values ? Shows the graph coordinates.

Simulates samples of given size, n, to build the correspondng experimental curves of the Student's t and of χ² (chi-square) distributions. For the latter, the two tails are made equal, as usual (not minimized), as the practical difference is possibly negligible.

Graphs are drawn for: Student's (i) t pdf, (ii) simulated t, (iii) t cdf, and (iv) simulated cumul. t; χ² (i) pdf, (ii) simulated χ², (iii) χ² cdf, and (iv) simulated cumul. χ². Asymptotically: t tends to the standard Gaussian (with peak going from ~0.36 to Gaussian ~0.39 [1⁄ √(2π) = 1⁄ ~2.5]; and χ² tends to Gaussian (μ=df; σ=√(2 df)), df = n − 1. The "symmetric" shaded probabilities are also shown.

References: Plate: StudChi2Reproduce

• Wikipedia: Table of selected values, Student's t.

• Wikipedia: Table of χ2 values vs p-values • Keisan Chi-square distribution (chart) Calculator

• 1619-01-30: Ricci, Michelangelo (†1682-05-12).

 
 
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Created: 2019-01-30 — Last modified: 2019-03-11