The below problem is from my introductory stats textbook, the chapter on random variables and probability distributions. I don't even know what's being asked, much less how to answer it. Any clues?
Arthroscopic meniscal repair was successful 70% of the time for tears greater than 25 millimeters (in 50 surgeries) and 76% of the time for shorter tears (in 100 surgeries). (a) Describe the random variable used in these probability statements. (b) Is the random variable continuous or discrete? (c) Explain why these probabilities do not add to 1.
So I've gone with (a) Binomial random variable (b) Discrete, because its binomial (c) They don't add to one as each is measuring the probability of a different thing.
I just want to make sure I'm not completely off-track here.