Question:
A survey was conducted by a group of students as a part of their environment awareness programme, in which they collected the following data regarding the number of a plants in 20 houses in a locality. Find the mean number of plants per house.
Which method did you use for finding the mean, and why?
Solution:
We may prepare the table as shown:
We know that mean, $\bar{X}=\frac{\sum f_{i} x_{i}}{\sum f_{i}}$
$=\frac{162}{20}$
$=8.1$
Hence, mean = 8.1
Direct method is easier than other methods. Therefore, we used direct method.