Answer:
-98.36
Explanation:
Given the data :
Marks 0-10 10-20 20-30 30-40 40-50 50-60
no.of students : 15. 20. 35. p. 10. 42
The given mean = 24
This is a grouped data:
The formula for the mean is :
Σfx / Σf
Where, x = midpoint ; f = frequency
The midpoint, x = (upper - lower limit) / 2
Midpoint of marks, x :
Marks _____ x ____ Frequency
0 - 10 _____ 5 ______ 15
10 - 20 ____ 15 _____ 20
20 - 30 ____25 _____35
30 - 40 ____35 _____ p
40 - 50 ____45 _____ 10
50 - 60____ 55 _____ 42
[(5*15) + (15*20) + (25*35) + (35*p) + (45*10) + (55*42)] / (15+20+35+p+10+42) = 24
(75+300+875+35p+450+2310) / (122 + p) = 24
(4010 + 35p) / (122 + p) = 24
4010 + 35p = 24(122+p)
4010 + 35p = 2928 + 24p
4010 - 2928 = 24p - 35p
1082 = - 11p
p = 1082 / - 11
p = - 98.36
Kindly check the distribution given again as obtaining a negative value isn't ideal.