# Ex.14.4 Q5 Statistics Solution - NCERT Maths Class 9

Go back to  'Ex.14.4'

## Question

Find the mean salary of $$60$$ workers of a factory from the following table:

 Salary (in Rs.) Number of Workers $$3000$$ $$16$$ $$4000$$ $$12$$ $$5000$$ $$10$$ $$6000$$ $$8$$ $$7000$$ $$6$$ $$8000$$ $$4$$ $$9000$$ $$3$$ $$10000$$ $$1$$ Total 60

Video Solution
Statistics
Ex exercise-14-4 | Question 5

## Text Solution

What is known?

Salary of $$60$$ workers in tabular form

What is unknown?

Mean of the given data

Steps:

We know that

Mean $$=$$ \begin{align} \frac{{\sum {{f_i}{x_i}} }}{{\sum {{f_i}} }}\end{align}

The value of $$\sum {{f_i}{x_i}}$$   and  $$\sum {{f_i}}$$ f can be calculated as follows.

 Salary $$(x_{i})$$ Number of Workers $$(f_{i})$$ $$f_{i} x_{i}$$ $$3000$$ $$16$$ \begin{align}16 \times 3000\\ =48000 \end{align} $$4000$$ $$12$$ \begin{align} 12 \times 4000 \\ =48000 \end{align} $$5000$$ $$10$$ \begin{align} 10 \times 5000 \\ =50000 \end{align} $$6000$$ $$8$$ \begin{align} 8 \times 6000 \\ =48000 \end{align} $$7000$$ $$6$$ \begin{align} 6 \times 7000 \\ =42000 \end{align} $$8000$$ $$4$$ \begin{align} 4 \times 8000 \\ =32000 \end{align} $$9000$$ $$3$$ \begin{align} 3 \times 9000 \\ =27000 \end{align} $$10000$$ $$1$$ \begin{align} 1 \times 10000 \\ =10000 \end{align} Total $$\sum f_{i}=60$$ $$\sum f_{i} x_{i}=305000$$

Mean salary  \begin{align} = \,\frac{{305000}}{{60}}\end{align}

Therefore, mean salary of $$60$$ workers is $$\rm{Rs.}\, 5083.33.$$

Learn from the best math teachers and top your exams

• Live one on one classroom and doubt clearing
• Practice worksheets in and after class for conceptual clarity
• Personalized curriculum to keep up with school