The mean and standard deviation of 100 observations 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 and standard deviation?

The mean and standard deviation of 20 observations are found to boe 10 and 2 respectively.On rechecking it was found that on observation 8 was incorrect.Calculate the correct mean and the standard deviation in each of the following cases.(ii)if it replaced by 12.

Mean and standard deviation of 100 items are 50 and 4 respectively. The sum of all squares of the items is

The mean and standard deviation of six observation are 8 and 4 respectively. If each observation is multiplied by 3, Find the new mean and new standard deviation of the resulting obervations.

If the coefficient of variation and standard deviation are 60 and 21 respectively, the arithmetic mean of distribution is

If the coefficient of variation and standard deviation are 60 and 21 respectively, the arithmetic mean of distribution is

The mean and median of 100 observations are 50 and 52 respectively. The value of the largest observation is 100. It was later found that it is 110 not 100. Find the true mean and median.

A scientist is weighing each of 30 fishes. Their mean weight worked out is 30 gm and a standard deviation of 2 gm. Later, it was found that the measuring scale was misaligned and always under reported every fish weight by 2 gm. The correct mean and standard deviation (in gm) of fishes are respectively :

The sum of the squares of deviations for 10 observations taken from their mean 50 is 250. The coefficient of variation is

The coefficient of variation of two distribution are 60 and 70. The standard deviations are 21 and 16 respectively, then their mean is