Statistics-And-Probability Question 630
Question: The mean of 20 observations is 15. On checking, it was found that two observations were wrongly copied as 3 and 6. If wrong observations are replaced by correct values 8 and 4, then the correct mean is
Options:
A) 15
B) 15.15
C) 15.35
D) 16
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Sum of all observations $ =20\times 15=300 $ Sum of correct observations $ =300-(3+6)+(8+4)=303 $ Correct mean $ =\frac{303}{20}=15.15 $
BETA
