Mean marks of 50 students were found to be 78.4. But later it was detected that 95 was misread as 59 and 25 was misread as 52. What is the difference between correct mean and incorrect mean?
- A. 0.04
- B. 0.08
- C. 0.12
- D. 0.18 ✓
Correct Answer: D. 0.18
Explanation
The net correction in the total sum is (95 - 59) + (25 - 52) = 36 - 27 = +9. The difference in the mean is the net sum correction divided by the number of students: \frac{9}{50} = 0.18.
Related questions on Statistics & Probability
- On an average, how many persons live in every pucca house?
- If 5000 more Kutcha houses are built, then what will be approximate change in angle for Kutcha houses in Pie Chart-I?
- If 300 families from the "Houseless" category shift into Kutcha houses, what will be the average number of families in every Kutcha house?
- What is the value of f?
- What is the median of the frequency distribution?