The mean and standard deviation of 20 observations are found to be 10 and 2 respectively. On rechecking, it was found that an observation 8 was incorrect. Calculate the correct mean and standard deviations in each of the following cases:
If it is replaced by 12.

The mean and standard deviation of 20 observations are found to be 10 and 2. respectively. On rechecking, it was found that an observation 8 was incorrect. Calculate the correct mean and standard deviation in each of the following cases: (i) If wrong item is omitted. (ii) If it is replaced by 12.

Calculate the mean and standard deviation of the following distribution :

Calculate the mean and standard deviation of the following distribution :

Find the mean and standard deviation for the following data :

Find the mean and standard deviation for the following data :

Find the mean and standard deviation for the following data :

Find the mean and standard deviation for the following data :

Calculate the mean and standard deviation for the following distribution :

Calculate the mean and standard deviation for the following distribution :