Problem You are working on decorating your
home for the holidays. You enjoy
hanging lights, and so far have invested
in $75 worth of lights. You notice a sale
that you can get strands of lights for $5
a box this week. Write an expression that
describes your total investment (money
spent) in lights, depending on how many
boxes (b) of lights you buy.

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 formula of a slope:

we have the points (-2, 7) and (2, 3). substitute:

h * s * a

h = history teacher

s = science teacher

a =   art teacher.

i see no data table, but just multiply the number of history teachers, science teachers, and art teachers.