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?