Pregunta 1
Pregunta
41. A set of families has the following distribution on number of children: x1, x2
Determine , if it is known that M(x) = 2 D(x) =1.2 ?
Pregunta 2
Pregunta
42. The lifetime of a machine part has a continuous distribution on the interval (0, 30) with
probability density function Calculate the probability that the
lifetime of the machine part is less than 6.
Respuesta
-
30/53
-
1/2
-
31/35
-
13/28
-
1/17
Pregunta 3
Pregunta
43. The lifetime of a machine part has a continuous distribution on the interval (0, 11) with
probability density function Calculate the probability that the lifteime of the machine part is less than 5.
Respuesta
-
1/17
-
7/20
-
10/11
-
19/35
-
7/11
Pregunta 4
Pregunta
44. A random variable X is given by the density function of distribution:n Find the integral function of distribution of the random variable X?
Pregunta 5
Pregunta
45. A random variable X is given by the density function of distribution: Find the integral function of distribution of the random variable X?
Pregunta 6
Pregunta
47. A random variable X is given by the integral function of distribution:
Find the mathematical expectation of the random variable X?
Pregunta 7
Pregunta
49. A random variable X is given by the integral function of distribution:
If , then find the dispersion of the random variable X?
Pregunta 8
Pregunta
51. The lifetime in hours of a certain kind of radio tube is a random variable having a probability density function given by: What is the probability that exactly 1 of 5 such tubes in a radio set will have to be replaced within the first 150 hours
of operation?
Respuesta
-
80/243
-
40/243
-
0
-
160/243
-
1/3
Pregunta 9
Pregunta
52. The lifetime in hours of a certain kind of radio tube is a random variable having a probability density function given by: What is the probability that exactly 3 of 5 such tubes in a radio set will have to be replaced within the first 150 hours
of operation?
Respuesta
-
80/243
-
40/243
-
0
-
160/243
-
1/3
Pregunta 10
Pregunta
53. A random variable X is given by the integral function of distribution:
Find the probability that random variable takes the values on .
Respuesta
-
117/125
-
208/125
-
63/125
-
113/125
-
1/5
Pregunta 11
Pregunta
54. A random variable X is given by the density function of distribution:
Find the value of C?
Pregunta 12
Pregunta
56. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| > 3.
Pregunta 13
Pregunta
57. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| > 3.
Pregunta 14
Pregunta
58. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| > 3.
Pregunta 15
Pregunta
59. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| < 1.
Pregunta 16
Pregunta
60. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| > 1.
Pregunta 17
Pregunta
61. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| > 2.
Pregunta 18
Pregunta
62. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| > 3.
Pregunta 19
Pregunta
63. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| > 5.
Pregunta 20
Pregunta
64. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| > 4.
Pregunta 21
Pregunta
65. A discrete random variable X is given by the following law of distribution:
By using the Chebyshev inequality estimate
the probability that |X – M(X)| < 4.
Pregunta 22
Pregunta
66. The probability that a shooter will beat out 10 aces at one shot is equal to 0.1 and the
probability to beat out 9 aces is equal to 0.3. Choose the correctly calculated probabilities of the
events.
Respuesta
-
P(beat out more than 8 aces) = 0.5
-
P(beat out more than 10 aces) = 0.2
-
P(beat out 9 or less aces) = 0.9
-
P(beat out 9 or less aces) = 0.3
-
P(beat out 9 or more aces) = 0.3
Pregunta 23
Pregunta
69. Three students pass an exam. Let be the event «the exam will be passed on “excellent” by the
i-th student» (i = 1, 2, 3). Which of the following events correctly expressed by and
their negations?
Pregunta 24
Pregunta
71. A random variable X is given by the integral function of distribution:
What does this tell us about the random
variable X? More than one option may be correct.
Respuesta
-
M (X) = 10
-
D(X) = 1/2
-
P (10 < X < 15) = 1/2
-
P (X < 0) = 0
-
M (X) = 3/10
Pregunta 25
Pregunta
74. The probability that a shooter hit in a target at one shot is equal to 0.8. The shooter has made 3
shots. Choose the correctly calculated probabilities of the events.
Respuesta
-
P(at least 1 of 3 shots will strike the target)=0.384
-
P(at least 1 of 3 shots will strike the target)=0.992
-
P(at least 2 of 3 shots will not strike the target)=0.189
-
P(at least 2 of 3 shots will strike the target)=0.845
-
P(neither of 3 shots will strike the target)=0.8
Pregunta 26
Pregunta
78. The probability to receive high dividends under shares at the first enterprise – 0.2, on the
second – 0.35, on the third – 0.15. Choose the correctly calculated probabilities that a
shareholder having shares of all the enterprises will receive high dividends.
Respuesta
-
P(at least on two enterprises) = 0.1315
-
P(exactly on two enterprises) = 0.4214
-
P(only at one enterprise) = 0.7
-
P(at least on one enterprise) = 0.4265
-
P(exactly on three enterprises) = 0.105
Pregunta 27
Pregunta
79. The probability to receive high dividends under shares at the first enterprise – 0.2, on the
second – 0.2, on the third – 0.3. Choose the correctly calculated probabilities that a shareholder
having shares of all the enterprises will receive high dividends.
Respuesta
-
P(only at one enterprise)=0.416
-
P(only at one enterprise)=0.7
-
P(at least on one enterprise)=0.426
-
P(at least on two enterprises)=0.354
-
P(exactly on three enterprises)=0.105
Pregunta 28
Pregunta
80. The first brigade has 6 tractors, and the second – 9. One tractor demands repair in each
brigade. A tractor is chosen at random from each brigade. Choose the correctly calculated
probabilities of events.
Respuesta
-
P(both chosen tractors demands repair)=1/54
-
P(one of the chosen tractors demands repair)=0.5
-
P(both chosen tractors demands repair)=0
-
P(both chosen tractors demands repair)=1/27
-
P(both chosen tractors are serviceable)=13/15
Pregunta 29
Pregunta
81. The first brigade has 5 tractors, and the second – 8. One tractor demands repair in each
brigade. A tractor is chosen at random from each brigade. Choose the correctly calculated
probabilities of events.
Respuesta
-
P(one of the chosen tractors demands repair)=11/40
-
P(one of the chosen tractors demands repair)=7/40
-
P(both chosen tractors demands repair)=1/20
-
P(both chosen tractors demands repair)=1/2
-
P(both chosen tractors are serviceable)=1/3
Pregunta 30
Pregunta
82. All of the letters that spell STUDENT are put into a bag. Choose the correctly calculated
probabilities of events.
Respuesta
-
P(drawing a S, and then drawing a T)=1/21
-
P(drawing a T, and then drawing a D)=1/42
-
P(selecting a vowel, and then drawing a U)=1/42
-
P(selecting a vowel, and then drawing a K)=1/42
-
P(selecting a vowel, and then drawing a T)=3/42
Pregunta 31
Pregunta
83. All of the letters that spell MISSISSIPPI are put into a bag. Choose the correctly calculated
probabilities of events.
Respuesta
-
P(of selecting a vowel, and then after returning the letter also drawing a M)=4/121
-
P(of drawing an I, and then after returning the letter also drawing a M)=3/121
-
P(of selecting a vowel, and then after returning the letter also drawing an O)=4/121
-
P(of selecting a vowel, and then after returning the letter also drawing a P)=6/121
-
P(of drawing a M, and then after returning the letter also drawing a S)=1/121
Pregunta 32
Pregunta
84. The first brigade has tractors n , and the second m . One tractor demands repair in each
brigade. A tractor is chosen at random from each brigade. Choose the correctly calculated
probabilities of events.
Respuesta
-
n=3, m=5, P(both chosen tractors demands repair)=1/15
-
n=3, m=6, P(one of the chosen tractors demands repair)=7/12
-
n=2, m=5, P(both chosen tractors demands repair)=0.3
-
n=2, m=3, P(both chosen tractors demands repair)=1/3
-
n=5, m=2, P(both chosen tractors are serviceable)=0.2
Pregunta 33
Pregunta
85. A jar of marbles contains 4 blue marbles, 5 red marbles, 1 green marble, and 2 black marbles.
A marble is chosen at random from the jar. After returning it again, a second marble is chosen.
Choose the correctly calculated probabilities of events.
Respuesta
-
P(green, and then red)=5/144
-
P(black, and then black)=1/12
-
P(red, and then black)=7/72
-
P(green, and then blue)=1/72
-
P(blue, and then blue)=1/6
Pregunta 34
Pregunta
86. If each of the regions in each spinner is the same size.
Choose the correctly
calculated probabilities of spinning each spinner.
Respuesta
-
P(getting a red sweater)=1/12
-
P(getting a white sweatshirt)=1/6
-
P(getting a white sweater)=5/12
-
P(getting a blue sweatshirt)=7/12
-
P(getting a blue t-shirt)=1/6
Pregunta 35
Pregunta
88. Mary is playing a game in which she rolls one die and spins a spinner.
Choose the correctly
calculated probabilities of spinning each spinner.
Respuesta
-
P(get the 1 and green)=0
-
P(get the 7 and red)=1/18
-
P(get the 3 and green)=1/18
-
P(get the 2 and black)=1/4
-
P(get the 1 and white)=1
Pregunta 36
Pregunta
90. Find the Bernoulli formula.
Pregunta 37
Pregunta
92. A coming up a grain stored in a warehouse is equal to 50%. What is the probability that the
number of came up grains among 100 ones will make from up to pieces (a grain – зерно)?
Pregunta 38
Pregunta
93. The probability of striking a target by a shooter at one shot is equal to 3/4 . Find the probability P
that at 100 shots the target will be struck no less than a and no more b times.
Pregunta 39
Pregunta
94. The probability of striking a target by a shooter at one shot is equal to 1/4. Find the probability P
that at 100 shots the target will be struck no less than a and no more b times.
Pregunta 40
Pregunta
95. Find approximately the probability that an event will happen exactly from a to b times at 400
trials if in each trial the probability of its occurrence is equal to 0.2.
Pregunta 41
Pregunta
96. Find approximately the probability that an event will happen exactly from a to b times at 484
trials if in each trial the probability of its occurrence is equal to 0.5.
Pregunta 42
Pregunta
97. A factory has sent 2500 good-quality products. The probability that one product has been
damaged at a transportation is 1/5 . Find the probability P that at the transportation it will be
damaged from to products.