5. Two mark example problems II

1. If the arithmetic mean of $7$ values is $30$ and if each value is divided by $3$, then find the arithmetic mean of new set of values.

 

Answer:

 

The arithmetic mean $=$

 

2. The average mark of $25$ students was found to be $78.4$. Later on, it was found that score of $96$ was misread as $69$. Find the correct mean of the marks.

 

Answer:

 

Mean $=$

 

(Note: Round off the answer to $2$ decimal places.)