In the verge of coronavirus pandemic, we are providing FREE access to our entire Online Curriculum to ensure Learning Doesn't STOP!

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