Statistics Help- Which of the following are continuous variables and which are discrete?

(a) speed of an airplane


(b) age of a college professor chosen at random


(c)number of books in the college bookstore


(d) weight of a football player chosen at random


(e) number of lightning strikes in the Rocky Mountain National Park on a given day

Statistics Help- Which of the following are continuous variables and which are discrete?
if the values the random variable can take on are discrete, i.e., countable, then you have a discrete random variable. for the most part, all other random variables are continuous. there are mixtures, but this is a very advanced idea.





a) the speed of an aircraft can be any value between 0 and the speed of light... any value, we can't count the number of values, the speed is a continuous random variable.





b) the age of the professor, if you look at just the year say 30, 31, 32, ... then it is discrete, if you let time be continuous, 43.213112, 43.21311213...... then it is continuous.





c) discrete, there are 0, 1, 2, 3, 4, 5, .... , k books in the store.








d) weight is the same as age, it is best considered continuous but can be discretized.





e) discrete, there are 0, 1, 2, 3, 4, 5, 6, ......