Download Entre 150 personas que fueron encuestadas como parte de un

1) Entre 150 personas que fueron encuestadas como parte de un estudio de
transporte urbano masivo, algunos vivían a más de 3 millas del centro de la
ciudad (A), algunos de ellos van en sus propios carros al trabajo (B) y otros
prefreirían cambiarse a transportación pública si hay disponibilidad de la misma
(C). Asuma que cada una de las 150 personas tienen la misma probabilidad de
ser seleccionada y halle la probabilidad de que la persona (tener en cuenta la
figura):
S
A
B
2
20
16
54
8
9
27
14
C
a. Viva a más de 3 millas del centro de la ciudad dado que la persona
cambiaria a transportación publica.
b. Maneja su carro al trabajo dado que la persona vive a más de 3 millas del
centro de la ciudad.
c. No le gustaría cambiar a transportación pública dado que la persona no
maneja su carro al trabajo.
2) Las 4 personas que atienden una gasolinera deben lavar el parabrisas del
carro de cada uno de sus clientes. Jack, quien sirve el 20% de todos los carros,
deja de lavar el parabrisas una vez en 20; Tom quien sirve el 60% de todos los
carros, deja de lavar el parabrisas una vez en 10; George, quien sirve 15% de
todos los carros, deja de lavar el parabrisas una vez en 10; y Peter, quien sirve
el 5% de todos los carros, deja de lavar el parabrisas una vez en 20. Si un
cliente se queja después de que su parabrisas no fue lavado, cual es la
probabilidad de que el carro haya sido servido por Jack?
2.98
A lot f 100 semiconductor chips contains 20 that are defective.
a) Two are selected, at random, without replacement, from the lot.
Determine the probability that the second chip selected is
defective.
b) Three are selected, at random, without replacement, from the lot.
Determine the probability that all are defective.
2-118
Software to detect fraud in consumer phones cards tracks the number of
metropolitan areas where calls originate each day. It is found that 1% of the
legitimate users originate calls from two or more metropolitan areas in a single
day. However, 30% of fraudulent users originate calls from two or more
metropolitan areas in a single day. The proportion of fraudulent users is 0.01%.
If the same user originates calls from two or more metropolitan areas in a single
day, what is the probability that the user is fraudulent?
2-121
Customers are used to evaluate preliminary product designs. In the past,
95% of highly successful products received good reviews, 60% of moderately
successful products received good reviews, and 10% of poor products received
good reviews. In addition, 40% of products have been highly successful, 35%
have been moderately successful, and 25% have been poor products.
a) What is the probability that a product attains a good review?
b) If a new design attains a good review, what is the probability that it will
be a highly successful product?
c) If a product does not attain a good review, what is the probability that it
will be a highly successful product?
2-168
The aligment between the magnetic tape and head in a magnetic tape
storage system affects the performance of the system. Suppose that 10% of the
read operation are degraded by skewed alignments, 5% by off-center
alignments, 1% by both skewness and off-center, and the remaining read
operations are properly aligned. The probability of a read error is 0.01 from a
skewed alignment, 0.02 from an off-center alignment , 0.06 from both conditions,
and 0.001 from a proper alignment. What is the probability of a read error?