Answer:
6
Explanation:
The mean of a list of test scores is 80
Adding an additional test score of 92 caused the mean to rise to 82
To find:
After this additional, how many total test are in the list ?
Solution:
Let the total number of test at first =

And sum of total score =

As we know, mean =


Multiplying both sides by


Now, as adding an additional test score of 92 caused the mean to rise to 82,


By dividing both sides by minus ( - )

By dividing both sides by 2

Thus, total number of test at first =
= 5
And, after this additional score added, total number of tests are
