Question

given the discrete probability distribution below:

x | 10 | 20 | 30 | 40 | 50 |

P(x) | 0.3 | 0.05 | 0.1 | 0.05 | 0.2 |

calculate:

a. E(x)

b. Var(x)

c. σx

Answer #1

Suppose X is a discrete random variable with probability mass
function given by
p (1) = P (X = 1) = 0.2
p (2) = P (X = 2) = 0.1
p (3) = P (X = 3) = 0.4
p (4) = P (X = 4) = 0.3
a. Find E(X^2) .
b. Find Var (X).
c. Find E (cos (piX)).
d. Find E ((-1)^X)
e. Find Var ((-1)^X)

1. Find the missing value indicated by (A) to make this a valid
discrete probability distribution.
x
-10
30
50
90
100
P(X=x)
0.05
0.10
0.25
0.15
A
2. Calculate the mean of the random variable associated with the
following discrete probability distribution. Do not round your
answer.
x
-1
0
1
P(X=x)
0.5
0.2
0.3

Analyze the scenario and complete the following:
Complete the discrete probability distribution for the given
variable.
Calculate the expected value and variance of the discrete
probability distribution.
The value of a ticket in a lottery, in which 2,000 tickets are
sold, with 1 grand prize of $2,500, 10 first prizes of $450, 20
second prizes of $125, and 55 third prizes of $40.
i.
xx
0
40
125
450
2,500
P(x)P(x)
Round probabilities to 4 decimal places
ii.
E(X)E(X) =...

You are given the following Discrete Probability Distribution
p(x)
Row
x
P(x)
1
1
0.1
2
2
0.156
3
3
0.147
4
4
0.2
5
5
0.222
6
6
0.056
7
7
0.02
8
8
0.099
1
Provide the following:
Mean (Expected value)
Variance
Standard Deviation
Graph (Histogram) of the Probability Distribution

The following table denotes the probability distribution for a
discrete random variable X.
x
-2
0
1
2
9
p(x)
0.1
0.3
0.2
0.3
0.1
The standard deviation of X is closest to
Group of answer choices
3.74
4.18
2.77
7.65
11

Analyze the scenario and complete the following:
Complete the discrete probability distribution for the given
variable.
Calculate the expected value and variance of the discrete
probability distribution.
The value of a ticket in a lottery, in which 2,000 tickets are
sold, with 1 grand prize of $4,000, 10 first prizes of $300, 30
second prizes of $100, and 65 third prizes of $20.
i.
x
0
20
100
300
4,000
P(x)
?
?
?
?
?
The above is also...

Given below is a bivariate distribution for the random variables
x and y
f(x,y)
x
y
0.3
80
70
0.4
30
50
0.3
50
60
a. Compute the expected value and the variance
for x and y
E(x)=
E(y)=
Var(x)=
Var(y)=
b. Develop a probability distribution for
x+y
x+y
f(x+y)
150
80
110
c. Using the result of part (b), compute E(x+y)
and Var(x+y) .
E(x+y)
Var(x+y)
d. Compute the covariance and correlation for x
and y. If required, round...

The probability distribution for the daily sales at Michael's
Co. is given below.
Daily Sales
(In $1,000s)
Probability
40
0.1
50
0.4
60
0.3
70
0.2
What is the variance of the above distribution?

approximate the following binomial probabilities for
this continuous probability distribution
p(x=18,n=50,p=0.3)
p(x>15,n=50,p=0.3)
p(x>12,n=50,p=0.3)
p(12<x<18,n=50,p,=0.3)

Consider the following discrete probability distribution.
x
−15
−5
15
20
P(X = x)
0.52
0.13
0.16
.
Complete the probability distribution. (Round your
answer to 2 decimal places.)
P(X = 15)
c.
What is the probability that the random variable X is
positive? (Round your answer to 2 decimal
places.)
Probability
d.
What is the probability that the random variable X is
greater than −10? (Round your answer to 2...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 4 minutes ago

asked 4 minutes ago

asked 23 minutes ago

asked 29 minutes ago

asked 31 minutes ago

asked 31 minutes ago

asked 33 minutes ago

asked 46 minutes ago

asked 48 minutes ago

asked 49 minutes ago

asked 52 minutes ago

asked 57 minutes ago