Home · Unit 4 · Topic 5 · Confidence intervals for means

Confidence intervals for means

Use x̄ and s to estimate μ and σ, to obtain approximate intervals covering desired proportions of values of a normal random variable and compare with an approximate confidence interval for μ.

u4-t5-s2-d6

Interactive

Individuals vs a CI for the mean

manipulative

A 95% interval for people is about x̄ ± 2s; a 95% CI for μ is about x̄ ± 2s/√n — only the CI shrinks with n.

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