SOLUTION: The mean of 205 items was 41. Later on it was discovered that two items were wrongly read as 99 and 7 instead of 185 and 44. Find the correct mean.

Algebra ->  Probability-and-statistics -> SOLUTION: The mean of 205 items was 41. Later on it was discovered that two items were wrongly read as 99 and 7 instead of 185 and 44. Find the correct mean.      Log On


   

Question 857896: The mean of 205 items was 41. Later on it was discovered that two items were wrongly read as 99 and 7 instead of 185 and 44. Find the correct mean.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The mean of 205 items was 41. Later on it was discovered that two items were wrongly read as 99 and 7 instead of 185 and 44. Find the correct mean.
-------
Total points with the wrong data: 205*41 = 8405
-----
Total on two items:: 185-99 + 44-7 = 86 + 37 = 123 points
------
Correct total points was 8405+123 = 8528
---
Correct mean = 8528/205 = 41.6
=====================================
Easier way to solve solve the problem
Total error = 123 pts
123/205 = 0.6
Add 0.6 to 41 to get 41.6 as the true mean.
===============================================
Cheers,
Stan H.
==================