Statistics And Probability Question 399
Question: An incomplete frequency distribution is given below
| Variate | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 | Total |
|---|---|---|---|---|---|---|---|---|
| Frequency | 12 | 30 | ? | 65 | 45 | 25 | 18 | 229 |
Median value is 46, the missing frequency is
Options:
A) 33.5
B) 35
C) 34
D) 26
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Median = 46 which lies in 40-50 class Median $ =l+h\frac{{ \frac{n}{2}-C_{f} }}{f} $ Where f= frequency of median - class $ {C_{f=}} $ Cumulative frequency of the class preceding the median class.
$ \therefore 46=40+10\frac{[ \frac{229}{2}-(x+42) ]}{65} $ Where x = frequency of class 30-40
$ \Rightarrow x=33.5=34. $
BETA
