Question

There are seven intersection with traffic signals between Tristan’s and Isolde’s homes. If x denotes the number of signals at which Tristan must stop because of a red light on a randomly selected trips to Isolde’s place, the probability distribution of x is

x	0	1	2	3	4
P(x)	0.15	0.05	0.10		0.40

Tristan never has to wait at more than four of the signals.

1. The missing entry in the table is

1. 0.30           (b) 0.25            (c) 0.00    (d) 0.15            (e) 0.35

2. The average number of intersections at which Tristan must stop because of a red light on trips to Isolde’s place is

1. 2.00           (b) 1.50            (c) 3.01            (d) 2.75            (e) 1.65

3. The probability that a person who has made a reservation for a trip on twelve-vehicle ferry will actually arrive and make the trip is 0.85. If to account for “no-shows” the ferry company makes 13 reservations for a particular trip, the chance that all 13 vehicles will show is about.

1. 0.15           (b) 0.06            (c) 0.02            (d) 0.12            (e) 0.08

Answer 1