Statistics-And-Probability Question 643
Question: In the following frequency distribution. Class limits of some of the class intervals and mid-vale of a class are missing. However, the mean of the distribution is known to be 46.5.
| Class intervals | Mid-values | Frequency |
|---|---|---|
| $x_1-x_2$ | 15 | 10 |
| $x_2-x_3$ | 30 | 40 |
| $x_3-x_4$ | M | 30 |
| $x_4-x_5$ | 75 | 10 |
| $x_5-100$ | 90 | 10 |
The values of $ x_1,x_2,x_3,x_4,x_5 $ respectively will be
Options:
A) $ (0,20,40,60,80) $
B) $ (40,50,60,70,80) $
C) $ (10,20,40,70,80) $
D) $ (0,19.5,39.5,69.5,80) $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] $ \frac{\Sigma x_{i}f_{i}}{\Sigma f_{i}}=46.5 $
$ \Rightarrow \frac{15\times 10+30\times 40+M\times 30+75\times 10+90\times 10}{10+40+30+10+10}=46.5 $
$ \therefore M=55. $ so the class intervals can be $ 10-20,20-40,40-70,70-80,80-100 $
BETA
