Confidence Interval/Examples

Examples of Confidence Intervals

$95 \%$ Confidence Interval

A $95 \%$ confidence interval is a confidence interval whose $\alpha$ parameter is:

$\alpha = 0 \cdotp 05$

Let $\bar x$ be the mean of a sample of $n$ observations from a normal distribution with unknown mean $\mu$ and known standard deviation $\sigma$.

Then a $95 \%$ confidence interval for $\mu$ is:

$\closedint {\bar x - \dfrac {1 \cdotp 96 \sigma} {\sqrt n} } {\bar x + \dfrac {1 \cdotp 96 \sigma} {\sqrt n} }$