(a) Write out a formula for the probability distribution of the random variable

Question

(a) Write out a formula for the probability distribution of the random variable n.

(b) What is the probability that Susan passes on the first try (n = 1)? (Round your answer to two decimal places.)

(c) What is the probability that Susan first passes on the second try (n = 2)? (Round your answer to three decimal places.)

(d) What is the probability that Susan needs three or more tries to pass Western Civilization? (Round your answer to three decimal places.)
(e) What is the expected number of attempts at Western Civilization Susan must make to have her (first) pass? Hint: Use for the geometric distribution and round. (Round your answer to two decimal places.)

Explanation / Answer

a)probability distribution of the random variable n=P(till (n-1) did not get passing grade and on nth term get first passing grade) =(0.16)n-1*0.84

b) probability that Susan passes on the first try =0.84

c) probability that Susan first passes on the second try =0.16*0.84 =0.1344

d)  probability that Susan needs three or more tries to pass Western Civilization =1-P(did not pass in first 2 tries)

=1-0.84-0.1344 =0.0256

e) expected number of attempts at Western Civilization Susan must make to have her (first) pass =1/p =1/0.84=1.19

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

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