Question

the arithmetic mean and the standard deviation of a series of 20 items are 20cms and 5cms respectively.But while calculating them an items 13 was misread as 30 .
find the correct mean and standard Deviation??​

Answer 1

The arithmetic mean and standard deviation of series of 20 items were calculated by a student as 20cm and 5cm.respectively.but while calculating them an item 13 was misread as 30.find the correct arithmetic mean and standards deviation.