An arrangement of marbles has 12 marbles in the first row and 10 rows in all. In each successive row one marble is added. What is the explicit rule for this situation, and how many marbles will be in the 10th row?Drag and drop the answers into the boxes to match the situation. Explicit ruleNumber of marbles in the 10th rowAn = 11 + 11n, An = 12 + n, An = 11 + n, An = 12 + 10n, 19, 20, 21,

The explicit rule for the number of marbles in 10th row is An= 12+ n-1.

Step-by-step explanation:

Therefore, for the remaining 9 rows out 10 rows ⇒ 9 marbles are added.

For n= 10, then

⇒ A10 = 12 + (10-1)

⇒ A10 =12+9 = 21

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.