#### In calculating the mean of grouped data, grouped in classes of equal width, we may use the formula $\bar{x}= a+\frac{\sum f_{i}d_{i}}{\sum f_{i}}$where a is the assumed mean. a must be one of the mid-points of the classes.  the last statement correct? Justify your answer.

Solution.   Grouped data are data formed by aggregating individual observations of a variable into groups.
Mean : It is the average of the given numbers. It is easy
to calculate mean. First of all add up all the numbers then divide by how many numbers are there.

This last statement is not correct because a can be any point in the grouped data it is not necessary that a must be mid-point.
Hence the statement is false.