Statistics And Probability Question 353

Question: The mean income of a group of 50 persons was calculated as Rs. 169. Later it was discovered that one figure was wrongly taken as 134 instead of correct value 143. The correct mean should be (in Rs.)

Options:

A) 168

B) 169

C) 168.92

D) 169.18

Show Answer

Answer:

Correct Answer: D

Solution:

[d] Given, $ 169=\frac{\Sigma x}{50} $ Correct value is 143. Hence, sum is short by 9.
$ \therefore M=\frac{169\times 50+9}{50}=169+\frac{9}{50}=169.18 $