If $\bar{x}_{1}, \bar{x}_{2}, \bar{x}_{3}, \ldots, \bar{x}_{n}$ are the means of $n$ groups with $n_{1}, n_{2}, \ldots, n_{n}$ number of observations respectively,then the combined mean $\bar{x}$ of all the groups taken together is given by:

  • A
    $\sum_{i=1}^{n} n_{i} \bar{x}_{i}$
  • B
    $\frac{\sum_{i=1}^{n} n_{i} \bar{x}_{i}}{n^{2}}$
  • C
    $\frac{\sum_{i=1}^{n} n_{i} \bar{x}_{i}}{2 n}$
  • D
    $\frac{\sum_{i=1}^{n} n_{i} \bar{x}_{i}}{\sum_{i=1}^{n} n_{i}}$

Explore More

Similar Questions

Represent the following data by a bar graph:
Name of student Kavya Ariv Ahaan Arya Arushi
Marks scored $90$ $80$ $50$ $60$ $40$

If the sum of $25$ observations is $900$, find the mean of those observations.

Represent the following data by a bar graph:
Score Frequency
$1$ $15$
$2$ $13$
$3$ $20$
$4$ $17$
$5$ $20$
$6$ $15$

Convert the given frequency distribution into a continuous grouped frequency distribution:
Class interval Frequency
$150-153$ $7$
$154-157$ $7$
$158-161$ $15$
$162-165$ $10$
$166-169$ $5$
$170-173$ $6$

In which intervals would $153.5$ and $157.5$ be included?

If $\bar{x}$ is the mean of $x_{1}, x_{2}, \ldots, x_{n}$ and $\bar{y}$ is the mean of $y_{1}, y_{2}, \ldots, y_{n}$. If $\bar{z}$ is the mean of $x_{1}, x_{2}, \ldots, x_{n}, y_{1}, y_{2}, \ldots, y_{n}$,then $\bar{z}$ is equal to

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo