27. Five mark example problem XI

The mean and standard deviation of \(15\) observations are found to be \(10\) and \(5\) respectively. On rechecking it was found that one of the observation with value \(8\) was incorrect. Calculate the correct mean and standard deviation if the correct observation value was \(23\)?

 

Answer:

 

Correct mean \(=\)

 

Correct standard deviation \(=\)