The stars in the big dipper may all appear to be the same distance from earth, but they are, in fact, very far from
each other. distances between stars are measured in light years, the distance that light travels in one year. the star
alkaid at one end of the big dipper is 138 light years from earth, and the star dubhe at the other end of the big
dipper is 105 light years from earth. from earth, it appears that alkaid and dubhe are 25.7° apart. find the
distance in light years between stars alkaid and dubhe

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.

-2

7 - 9 = -2

reversed:

-2 + 9 = 7