Population Mean (Leaving Cert Mathematics): Quizzes

Average of entire population

$\mu$

$\bar{x}$

$\mu = \frac{\sum x}{N}$

$\bar{x} = \frac{\sum x}{n}$

When measuring entire population is impractical

Range where population mean likely falls

$\bar{x} \pm z \times \frac{s}{\sqrt{n}}$

$1.96$

$N$ is population size, $n$ is sample size

$80$

Sample standard deviation