[c.f. PSBE 4.32] Spill or spell? Spell-checking software catches "nonword errors" that result in a string of letters that is not a word, as when "the" is typed as "teh". When undergraduates are asked to write a 250-word essay (without spell-checking), the number X of nonword errors has the following distribution: Value of X 0 Probability 0.1 0.2 1 3 4 0.3 a) Is X a discrete random variable or a continuous random variable? Why? b What probability should replace "?" in the distribution of X in the table 0.2 above? c Write the event "at least one nonword error" in terms of X. What is the probability of this event? d) Describe the event X S2 in words. What is its probability? What is the probability that X