Question

the mean of following frequency table is 25.2 and total frequency is 50.find the missing frequencies x and y

Answer 1

x =10or 9
y=9 or 10.. it may answer

Answer 2

Answer:

The value of x is 12 and the value of y is 11.

Step-by-step explanation:

It is given that the mean of following frequency table is 25.2 and total frequency is 50.

The given table is

C.I.                     Frequency(f)           Mid value(m)         f×m  

0-10                            8                          5                        40

10-20                          x                          15                      15x

20-30                        10                         25                     250

30-40                         y                          35                     35y

40-50                         9                          45                     405

Total                        27+x+y                                       695+15x+35y

From the above table it is noticed that the sum of frequency is 27+x+y.  Total frequency is 50.

$x+y+27=50$

$x+y=23$                          ..... (1)

$Mean=\frac{\sum fm}{\sum f}$

$25.2=\frac{695+15x+35y}{27+x+y}$

$51x-49y=73$                   ..... (2)

On solving (1) and (2), we get

$x=12$

$y=11$

Therefore the value of x is 12 and the value of y is 11.