The length of a scale is 30 cm and it's thickness is 5mm. What is the ratio of the
thickness of the scale of that of it's length?

Length of a scale = 30 cm

Thickness of a scale = 5mm

To find their ratio let us first make their units equal .

30 cm = 30 × 100 mm = 300 mm

Length of a scale = 300 mm

Thickness of a scale = 5 mm

Ratio of thickness of scale to length of scale =

= 5 : 300 = 5/300

Let us simplify 5/300 by dividing it's numerator and denominator by 5 .

= 5 ÷ 5 / 300 ÷ 5

= 1/60

= 1 : 60 mm

Therefore , the ratio of the thickness of scale to the length of scale is 1 : 60 mm .

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.