30. Five mark exercise problem III

A wall clock strikes the bell once at \(1\) o' clock, \(2\) times at \(2\) o' clock, \(3\) times at \(3\) o' clock and so on. How many times will it strike in a particular day. Find the standard deviation of the number of strikes the bell make a day.

 

Answer:

 

Standard deviation \(=\)