Question

2) The mean of the following frequency distribution is 20. Determine the value of x
Class
0-10 10-20 20-30 1 30-40 | 40-50
Frequency 5 6x3xx
2x​

Answer 1

The value of x is 64.                

Question : The mean of the following frequency distribution is 20. Find the missing frequency x.

Class                0 - 10      10 - 20      20 - 30      30 - 40      40 - 50

Frequency           8             x               10                11                9    

To find : value of x.                                

Given :

Class                 0 - 10      10 - 20      20 - 30      30 - 40      40 - 50

Frequency           8             x               10                11                9    

Mid-value             5           15              25               35              45                  

Mean = 20

To find the value of x :

$\frac{(8\times5)+ 15x + (10\times25) + (11\times35) + (9\times45)}{8+x+10+11+9} = 20$

$\frac{40 + 15x +250 +385 + 405 }{x+ 38} = 20$

40 + 15$x$ + 250 + 385 + 405 = ( $x$ + 38 )( 20 )

1080 + 15$x$  = 20$x$ + (20 × 38)

1080 + 15$x$ = 20$x$ + 760

Arranging "x" terms,

1080 - 760 = 20$x$ - 15$x$

5$x$ = 320

$x$ = $\frac{320}{5}$ = 64

$x$ = 64.        

Therefore, the value of x is 64.

Note : Given question is incomplete so, the above problem is of similar type.Refer the above problem and solve.

   

To learn more...

1. The median class of a frequency distribution is 125-145. The frequency of the median class and cumulative frequency of the class preceding to the median class are 20 and 22 respectively. Find the sum of frequencies if the median is 137

brainly.in/question/14463900

2. Find the value of a and prepare a frequency distribution table for drawing a frequency polygon. draw a frequency polygon.

class :-20-30,30-40,40-50,50-60,

Frequency :-a, 2a, 3a, a, total 70

brainly.in/question/14463900