What is a cross-sectional study? Choose the correct answer below. A.
Cross-sectional studies are observational studies that are retrospective, meaning that they require individuals to look back in time or require the researcher to look at existing records.
B.
Cross-sectional studies are observational studies that collect information about individuals at a specific point in time or over a very short period of time.
C.
Cross-sectional studies first identify a group of individuals to participate in the study. These individuals are then observed over a period of time. Over this period of time, characteristics about the individual are recorded.
D.
Cross-sectional studies are a list of all individuals in a population along with certain characteristics of each individual.

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.

the olimpics is not going to wokk out

step-by-step explanation:

1,407.5 hours

step-by-step explanation:

we first convert all the time to hours and then sum them up.

there are 24 hours in 1 day, in 58 days, there are 24 x 58 = 1,392 hours.

there are 60 minutes in 1 hour, thus, 30 minutes will be equivalent to 30 / 60 = 0.5 hours.

therefore, the number of hours it will take mercury to complete a full rotation is 1,392 + 15 + 0.5 = 1,407.5 hours