From beginner to expert, IDNLearn.com has answers for everyone. Ask anything and receive thorough, reliable answers from our community of experienced professionals.

The mean of the following frequency distribution is 25.2. Find the missing frequency x.

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

Frequency
8
x
10
11
9​


Sagot :

Answer:

Solution:-

Frequency Distribution     Frequency     Mid values     F*M

0 - 10                                    8                     5                40

10 - 20                                  x                    15               15x

20 - 30                                 10                   25               250

30 - 40                                 11                   35               385

40 - 50                                  9                    45               405

_____________________________________________________

                                         Σf = 38+x                      Σfm = 1080+15x

______________________________________________________

Given Mean = 25.2

Mean = Σfm/Σf

25.2 = 1080+15x/38+x

25.2 × (38+x) = 1080+15x

957.6+25.2x = 1080+15x

25.2x - 15x = 1080 - 957.6

10.2x = 122.4

x = 122.4/10.2

x = 12

Missing frequency = 12  Answer