Consider a small unit of a factory where there are $5$ employees: a supervisor and four labourers. The labourers draw a salary of $Rs. 5,000$ per month each,while the supervisor gets $Rs. 15,000$ per month. Calculate the mean,median,and mode of the salaries of this unit of the factory.

(A) Mean = $\frac{5000+5000+5000+5000+15000}{5} = \frac{35000}{5} = 7000$.
So,the mean salary is $Rs. 7000$ per month.
To obtain the median,we arrange the salaries in ascending order:
$5000, 5000, 5000, 5000, 15000$.
Since the number of employees in the factory is $5$,the median is given by the $\left(\frac{5+1}{2}\right)^{th} = 3^{rd}$ observation.
Therefore,the median is $Rs. 5000$ per month.
To find the mode of the salaries,we observe that $5000$ occurs the maximum number of times in the data. So,the modal salary is $Rs. 5000$ per month.
Comparing the three measures of central tendency,we see that the mean salary of $Rs. 7000$ does not give an accurate estimate of the wages of the majority,while the median and mode of $Rs. 5000$ represent the data more effectively. Extreme values in the data affect the mean,which is a weakness of this measure.