The mean and standard deviation of a group of 200 candidates are 40 and 15 respectively. Later on it was found to that one observation 43 was incorrectly copied down as 34. find the correct mean and standard deviation.

The mean and standard deviation of a random variable X are 10 and 5 respectively. Match the following.

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.

The mean and standard deviation of a group of 100 observations were found to be 20 and 3, respectively. Later on it was found that three observations were incorrect, which were recorded as 21, 21 and 18. Find the mean and standard deviation if the incorrect observations are omitted.

The mean and standard deviation of random variable X are 10 and 5 respectively, then E((X-15)/(5))^(2)= ____

The mean and standard deviation of 100 observation were calculated as 40 and 5.1, respectively by a student who took by mistake 50 instead of 40 for one observation . What are the correct mean standard deviation?

Mean and standard deviation of the random variable X are (7)/(3) and (14)/(9) respectively. Then find value of n and p.

Mean and standard deviation of 100 items are 50 and 4, respectively . Find the sum of all the item and the sum of the squares of the items.

Find the mean and standard deviation using short-cut method: