Bissoy.com
Doctors Medicines MCQs Q&A

The mean of 10 observations is 27. Later, it was found that two observations were wrongly copied as 13 and 14. If wrong observations are replaced with 18 and 19, then what is the new mean? 

The mean of 10 observations is 27. Later, it was found that two observations were wrongly copied as 13 and 14. If wrong observations are replaced with 18 and 19, then what is the new mean?  Correct Answer 28

Formual used

Mean = (Sum of all observations/number of observation)

Calculation

Sum of 10 observations = mean  number of observations = 27 × 10 = 270

Now, sum of 10 observations after replacement of wrong observations = 270 - (13 + 14) + (18 +19) = 270 - 27 + 37 = 280

Hence, new mean = 280/10 = 28

Related Questions

The mean of 20 observations is 17. On checking, it was found that the two observations were wrongly copied as 3 and 6. If the wrong observations are replaced with correct values 8 and 9, then what is the correct mean? 
In a class of five students P, Q, R, S and T, only one student is known to have copied in the exam. The disciplinary committee has investigated the situation and recorded the statements from the students as given below. Statement of P: R has copied in the exam. Statement of Q: S has copied in the exam. Statement of R: P did not copy in the exam. Statement of S: Only one of us is telling the truth. Statement of T: R is telling the truth. The investigating team had authentic information that S never lies. Based on the information given above, the person who has copied in the exam is
The mean of 5 observations is 60, the mean of 10 observations is 30 and the mean of 15 observations is 20. The mean of all the 30 observations is-
The mean of 10 observations is 13. Two more observations are included and the new mean becomes 14. The mean of two new observations is
The median for an odd number of observations is _________ where n is the number of observations. rank on the ascending order of observations b) rank on the ascending order of observations c) Average of and (n/2) rank on the ascending order of observations d) (n/2) rank on the ascending order of observations
If the mean of m observations out of n observations is n and the mean of remaining observations is m, then what is the mean of all n observations?
The mean of 50 observations was 36. It was found later that an observation 48 was wrongly taken as 23. The corrected new mean is :
The average marks of 60 students of a class were found to be 64. Later, it was found that marks of two students were wrongly read as 42 and 28 in place of 24 and 76 respectively. Then what is the correct average marks?
Mean of 60 observations is 66. Later, it was found that an observation 24 was wrongly taken as 42. What is the corrected mean?
How does number of observations influence overfitting? Choose the correct answer(s).Note: Rest all parameters are same
1. In case of fewer observations, it is easy to overfit the data.
2. In case of fewer observations, it is hard to overfit the data.
3. In case of more observations, it is easy to overfit the data.
4. In case of more observations, it is hard to overfit the data.