# Definition:Mean of Grouped Data

## Definition

Let $\mathsf C_1, \mathsf C_2, \cdots, \mathsf C_n$ be classes of data.

Let $m_i$ be the class mark of the $i$th class.

Let $f_i$ be the frequency of the $i$th class.

The mean of the grouped data for $\mathsf C_1, \mathsf C_2, \cdots, \mathsf C_n$ is defined as:

$\displaystyle \bar x_{\mathsf C} := \frac 1 n \sum_{i \mathop = 1}^n m_i f_i$