Determine the value of c for the distribution of random variable X that has a discrete distribution with the following probability function, f(x) =  cx for x = 1, . . . , 5 0 otherwise [2 marks] Data...

1 answer below »
Determine the value of c for the distribution of random variable X that has a discrete distribution with the following probability function, f(x) =  cx for x = 1, . . . , 5 0 otherwise [2 marks] Data Source: Probability and Statistics M. DeGroot & M. Schervish, Addison-Wesley (2002). (b) Let X be the ticket price for an event. supose that the probability distribution of X is: X 100 120 140 160 180 200 p 0.22 0.2 0.18 0.16 0.13 0.11 (i) What is the probability that a randomly selected attendee paid more that $140 for the ticket? [2 marks] (ii) What is the probability that a randomly selected attendee paid less than $160? [2 marks] (iii) Compute the expected value and standard deviation of X. [4 marks] Data Source: Statistics and data with R. Y. Cohen & J. Cohen, Wiley (2008). Question 2 - 6 marks Suppose that a box contains 7 red balls and and 3 blue balls. If 5 balls are selected at random, without replacement, determine the probability function of the number of red balls that will be obtained using (a) Counting methods 3 marks (b) Simulation 3 marks . Data Source: Probability and Statistics M. DeGroot & M. Schervish, Addison-Wesley (2002). 1 Question 3 - 8 marks Suppose that the life expectancy X of each member of a group of people is a random variable having an exponential distribution with parameter ? = 1 50 years. (a) For an individual from this group, compute the probability that: (i) He will survive to 65, 2 marks (ii) He will live to be at least 70 years old, given that he just celebrated his 40th birthday, 3 marks (b) For what value of c is P(X > c) = 1 2 ? 3 marks f(x|?) = ?e-?x ? > 0, x > 0 Data Source: A Course in Mathematical Statistics. G Roussas, Academic Press (1997). Question 4 - 6 marks A uniform distribution is defined with density function f(x; a, ß) = 1 (ß - a) ß > a and x ? (a, ß) Show that (a) E(X) = a + ß 2 [2 marks] (b) var(X) = (ß - a) 2 12 [4 marks] Data Source: A Course in Mathematical Statistics. G Roussas, Academic Press (1997). Question 5 - 6 marks Let X be a random variable with probability density function f(x) = ?e-?(x-a) x > a (a) Find its Moment Generating Function MX(t) for those t’s that exist. [3 marks] (b) Calculate E(X) [1 mark] (c) Calculate s 2 (X) [2 marks] Data Source: A Course in Mathematical Statistics. G Roussas, Academic Press (1997)
Answered Same DayDec 23, 2021

Answer To: Determine the value of c for the distribution of random variable X that has a discrete distribution...

David answered on Dec 23 2021
136 Votes
Q1 (a)
    Determine the value of c for the distribution of random variable X that has a discrete
distribution with the following probability function,
f(x) =
1,2,3,4,5
0
cxforx
Otherwise
=
ì
í
î
Solutio
n: The probability distribution table:
X
1
2
3
4
5
P(X)
c
2c
3c
4c
5c
We know that ∑P(x) = 1
c+2c+3c+4c+5c = 1
15c = 1
Answer: c = 1/15
    
    (i) What is the probability that a randomly selected attendee paid more that $140 for the ticket?
P(x>140) = P(x = 160)+ P(x = 180) + P(x = 200)
=0.16 + 0.13 + 0.11
= 0.40
Answer: P(x>140) = 0.40
    
    (ii) What is the probability that a randomly selected attendee paid less than $160?
P(x<160) = P(x = 100)+ P(x = 120) + P(x = 140)
=0.22 + 0.20 + 0.18
= 0.60
Answer: P(x<160) = 0.60
    
    (iii) Compute the expected value and standard deviation of X.
X
100
120
140
160
180
200

P(X)
0.22
0.20
0.18
0.16
0.13
0.11
XP(X)
22
24
25.2
25.6
23.4
22
142.2
X2P(X)
2200
2880
3528
4096
4212
4400
21316
Expected value = E(X) = ∑x.P(x)
= 100(0.22) + 120(0.20) + 140(0.18) + 160(0.16) +180(0.13) + 200(0.11)
= 22 + 24 + 25.2 + 25.6 + 23.4 + 22
= 142.2
Standard deviation =
s
(X) =
(
)
2
2
()()
xPxEX
-
å
=
(
)
2
21316142.2
-
=
2131620220.84
-
=
1095.16
= 33.09
Answer: The expected value of X = 142.2 and standard deviation of X = 33.09
    2(a)
    Number of red balls = 7
Number of blue balls = 3
5 balls are drawn randomly without replacement
So the all possibilities are as follows
Either (2 red and 3 blue balls) or (3 red and 2 blue balls) or (24 red and 1 blue balls) or(5 red and 0 blue ball)
The probabilities will be as follows
P(2 red and 3 blue) =
73
23
10
5
CC
C
´
=
21
252
=
1
12
P(3 red and 2 blue) =
73
32
10
5
CC
C
´
=
5
12
P(4 red and 1 blue)...
SOLUTION.PDF

Answer To This Question Is Available To Download

Related Questions & Answers

More Questions »

Submit New Assignment

Copy and Paste Your Assignment Here