2. Mary's test average after 8 tests is 80. Her score on the 9th test was 71. If all 9 tests are weighted equally, what
is Mary's test average for all 9 tests?
A. 71
B. 75.5
C. 77
D. 79
E. 80

D

Step-by-step explanation:

since her test average for the first 8 tests is 80, the sum of all the scores for the first 8 tests is 640. Since her 9th test is 71, we do 640+71=711. To find the average of all 9 tests, we do 711/9 = 79

D

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.

answer: the first graph

step-by-step explanation: