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
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Σf = 38+x Σfm = 1080+15x
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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
