Spell-checking software catches \"nonword errors,\" which are strings of letters

Question

Spell-checking software catches "nonword errors," which are strings of letters that are not words, as when "the" is typed as "eth." When undergraduates are asked to write a 250-word essay (without spell-checking), the number X of nonword errors has the following distribution.

(a) Sketch the probability distribution for this random variable.

(b) Write the event "at least one nonword error" in terms of X.

A. X 2

B. X > 1

C. X 1

D. X 1

What is the probability of this event?


(c) Describe the event X 2 in words.

A. no more than three nonword errors

B. less than 2 nonword errors    

C. more than 2 nonword errors

D.no more than two nonword errors

What is its probability?


What is the probability that X < 2?

Explanation / Answer

a) The correct option is Option-B)

b) The correct option is Option-C) X 1

c) The correct option is Option-D) no more than two nonword errors

P(X < 2) = P(X = 0) + P(X = 1) + P(X = 2)

              = 0.12 + 0.19 + 0.31

              = 0.62

P(X < 2) = P(X = 0) + P(X = 1)

              = 0.12 + 0.19

              = 0.31

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.