<prompt> In the bih weight of each of the 10 babies born in a hospital in a day is found to be 2.8 kgs, then the standard detion of this sample will be ?2.8010.28  <response>: Ans. is b i.e., 0 o Standard detion measures the variation dispersion of an individual data from the mean. o ST tells how tightly all the values are clustered around the mean in a set of data. o High standard detion indicates that the data is dispersed away from the mean. o Low standard detion indicates that the data points tend to be very close to mean, i.e. data points are clustered close to the mean. o For example, the average height for adult men in USA is about 70 inches, and standard detion is 3 inches. Then - i If dispersion of mean is 1 SD -- most men about 68 have a height within 3 inches of the mean 67-73 inches. ii If dispersion of mean is 2 SD -- almost all men 95 have a height within 6 inches of the mean 64 - 76 inches. iii If dispersion is zero SD -- all men would be exactly 70 inches. o That means greater the standard detion greater will be the data spread away from standard detion. Coming back to question o Here all newborn babies has 2.8 kgs of weight. o That means there is no dispersion from mean. o So, standard detion is zero. 