Ngee Ann PolytechnicSchool of Business and AccountancyTutorial 04: A Survey of Probability Concepts

Tutorial QuestionsCustomised Text, Adapted from Statistical Techniques in Business and Economics (16th Edition) :

p 107 Q 16 P 108 Q 22p 117 Q 28p 121 Q 35, 37p 130 Q 62p 131 Q 64, 66, 69p.132 Q 77, 79

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Answers

Q16. No, they are not mutually exclusive because it is possible that both are “heads” and tails. Yes they are complements.

Q22a.

Q22b.

Q22c.

The probability of 0.35 is called as a joint probability.

No, because it is possible that the visitors to the Rocky Mountain would visit both attractions together.

Q28a.

Q28b.

Q35. P(N) = 0.7 P(D) = 0.3 P(W/D) = 0.5 P(W/N) = 0.9

P(W/N) =

Q37. P(CC) = 0.3 P(C) = 0.3 P(DC) = 0.4 P(C/>50) = 0.2 P(CC/>50) = 0.9 P(DC/>50) = 0.6

P(C/>50) =

=

Q62a.

Q62b.

Q62c.

P(S) = 0.4 P(~S) = 0.6

P(~S) = 0.6

1 – P(~S) =

Q64a.

Q64b.

Q64c.

Q64d.

P(prepared their own taxes) =

P(both prepared their own taxes) =

P(three prepared their own taxes) =

P(neither of which has their tax prepared by H&R) =

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Q66a.

Q66b.

Q66c.

Q66d.

P(made more than $1 million) =

P(made more than $1 million or shareholders lost money) =

P(made more than $1 million given the shareholders lost money) =

P(both made more than $1 million) =

Q69a.

Q69b.

P(not perfect CDs) =

P(cannot be used at all) =

Q77.

Q79a.

Q79b.

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