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.
For example, the sample mean is an estimator of a population mean. If the sample mean of a particular sample 75 then the value 75 is the estimate for the population mean. Just as there are multiple possible sample statistics, there are are many possible estimators.