The first of two samples has 100 items with mean 15 and standard deviation 3. If the whole group has 250 items with mean 15.6 and standrd deviation `sqrt(13.44)` then standard deviation of second group is

The first of two samples has 100 times with mean 15 and standard deviations 3. If the whose group has 250 items with mean 15.6 and standard deviation sqrt(3.44) Find the standard deviation of the second group.

The first of the two samples have 100 items with mean 15 and S.D.3. If the whole group has 250 items with mean 15.6 and S.D.=sqrt(13.44) then S.D. of the second group is

If the first sample A of 100 items has the mean 15 and standard deviation 3 and second sample B has 150 items. If the combined mean and standard deviation of itmes of both the sample is 15.6 and sqrt(13.44) then then standard deviation of items of sample B is

Out of total sample survey of 100 nuts, in a first sample survey of 35 items has mean 80 and standard deviation 4. A second sample survey of 65 items has mean 70 and standard deviation 3. Find the mean and variance of combined 100 sample nuts.

A sample of 35 observations has mean 80 men and standard deviation 4. A second sample of 65 observations has mean 70 and standard deviation =3. Find the combined mean and standard deviation.