Statistics Question: What's a ratio scale variable? And...?

Question

Professor says, "Students will need to obtain a dataset of their choice (the source needs to be provided and verifiable). The dataset will need to have AT LEAST 50 observations and three variables. The dataset must have at least one ratio scale variable and at least one categorical variable."

Does this dataset meet the requirements?
http://nces.ed.gov/programs/coe/2006/section1/table.asp?tableID=440

Which one is the ratio-scale variable?

Thanks!!!

I need to know what a ratio-scale variable is and also, if the dataset i provided a link to meets the requirements listed by my professor.

I'm confused, too...or else I wouldn't be here!

Thanks!

Answer 1

Sorry to say, you better pass on this data set.

Note that each row of numbers totals 100, as these are percentages, so the variables are correlated, and have limited application.

I think your professor wants two of the variables to be somewhat independent, meaning one is not a function of the other. Such as gas mileage and price, for example, if you had a list of automobile makes.

Ratio variables are those in which the ratio of two of the numbers have meaning, such as miles per gallon, for example. If car A gets 15 mpg and car B gets 20 mpg, you can take the ratio of the two: 15/20 and compute 0.75, meaning car A gets 75% of the mileage of car B.

Answer 2

I'll give you an example of a dataset that would qualify.

Weather stats: say in your hometown or wherever.

You need three variables.

Say the high and/or low temperatures for each day for the last 50 days.


Daily average barometer readings for the same period

daily rainfall (or say hours of sunshine) for the same period.

These are ratio scale variables according to the definition. Go to this link and scroll down to ratio measurement. Your dataset doesn't have one.

http://en.wikipedia.org/wiki/Ratio_measurement

Answer 3

I am confused. What do u need to know

Answer 4

You may find your answer here:

http://www.upa.pdx.edu/IOA/newsom/pa551/lecture1.htm

Guido