2. Rosa and her friends went kayaking at a local lake. Rosa paid $12 for
the use of the kayak and paid $7.50 for every 30 minutes on the lake.
She paid a total of $34.50. How many hours did Rosa and her friends
spend on the lake?
Solve it!
Write It!

  3 hours

Step-by-step explanation:

For h hours, the charges for Rosa's rental were ...

  34.50 = 12.00 + 7.50h

  22.50 = 7.50h . . . . . . . . . subtract 12.00

  22.50/7.50 = h = 3  . . . . . divide by the coefficient of h

Roas spent 3 hours on the lake.

the answer is 28

step-by-step explanation:

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.