Since the sample size is always smaller than the size of the population, the sample meana. must always be smaller than the population meanb. must be larger than the population meanc. must be equal to the population meand. can be smaller, larger, or equal to the population mean

Step-by-step explanation:

We know that the sample size is smaller than the size of the population, because it's a subset that must represent the population.

However, that doesn't mean the sample mean has to be smaller than the population mean, actually this stats can be smaller, equal or larger, it depends on another factors.

Therefore, the right answer is the last choice

2

step-by-2step explanation:

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.