Question

Factors are qualitative data that are associated with categorization or the description of an attribute. Factors are often (but not always) represented with words, like colors or names of things. On the other hand, numeric data are generated by numeric measurements. R can store values as factors or numbers, but sometimes you have a choice of how to represent values.

1) I have two apples, one banana, one cherry.  Does it make sense to calculate the "average" of these things? Would you code that as a factor or a numeric value in R?

2) I have four quiz scores: 94, 93, 85, and 0. What is the mean (average) of my quiz scores? Would you code this as a factor or a numeric value in R?

3) In another class, I received these grades on my quizzes: two As, one B, and one F. What is the mean (average) of my grades? Would you code that as a factor or a numeric value in R?

4) How would you explain the difference in mean values obtained in #2 and #3 above?

There is no requirement to use sources from the Internet, but if you use an idea or a quotation from any source, it should be cited (such as putting the author and year at the end of the sentence and then adding a reference at the end to describe the source).

Answer 1

Answer:------------

1). No, we cannot make average on two apples, one banana, one cherry, because they are different kind of fruits, not number.
Then, I would code Fruit as factors, since fruit is qualitative not quantitative.

2). I use R to find out the mean (average), the result is following:
===> x <= c (94, 93, 85, 0)
====> mean(x)
So, mean (average) = (94+93+85+0) / 4 = 68
Then, I have coded the four quiz scores (94, 93, 85, and 0) as numeric value in R.

3). No, average is not possible here, because the letter grades are not numbers.
I would code the grades (letters) as factors in R.

4). We cannot make different between #2 and #3 above, since #2 is numeric whereas #3 is factor. We should convert factor to numeric first, before doing subtraction operation.