To understand the critical nature of sleep to our children's growth and development, we need to understand more about what sleep does, what healthy sleep is, and what happens when children do not get either the right amount of sleep, the best quality sleep, or both.lthough this may seem apparent, many of us actually do not allow our children to get the critical sleep they need to develop and function properly. It's certainly not something we do on purpose. As a matter of fact, we often don't think much of it, and that is the problem.
Sample Mean. The sample mean is the average of all the items in a sample (a group of observations). The following is the formula for the sample mean x of a set {x1, x2, ..., xn} of n observations from a given distribution: The population mean is the average of all the items in a population. Because a population is usually very large or unknown, the population mean is usually an unknown constant. An estimate of the population mean is the sample mean.
1 Population and sample. In statistics, a population is an entire set of objects or units of observation of one sort or another, while a sample. is a subset (usually a proper subset) of a population, selected for particular study (usually because it is impractical. to study the whole population).