Consider the following grouped frequency distribution:

x f

0-10 8

10-20 12

20-30 10

30-40 p

40-50 9

If the mean of the above data is 25.2, then what is the value of p?

A) 9	B) 10
C) 11	D) 12

Answer: C) 11

Explanation:

Mean = (sum of fixi/ (sum of f) = (8*5 + 12*15 + 10*25 + P*35 +9*45) / (8+12+10+P+9) = 25.2

(875 + 35P)/(39+P) = 25.2

P = 11

Subject: Average
Exam Prep: Bank Exams