Question

In: Statistics and Probability

Here is another infectious disease model. Once a person becomes infected, the time X, in days,...

Here is another infectious disease model. Once a person becomes infected, the time X, in days, until the person becomes infectious (can pass on the disease) can be modeled as a Weibull random variable with density function

  

f(x,α,β) = (α/βα)xα−1e−(x/β)α

for 0 ≤ x ≤ ∞ and 0 otherwise with α = 3.7 and β = 7.1

α is the shape parameter and β is the scale parameter. Hint: Solve this with the built-in R functions for the Weibull distribution (dweibull(),pweibull(), qweibull()) not f as defined above. Otherwise you may get intermediate values too large to use. For a) and b) the text (and notes) give formulas for the answers. You can calculate from these formulas. Note that these formulas use the gamma function. Γ(α) is the gamma function. In R, there is a built-in function gamma() which calculates this.
a) What is the expected value of X?

b) What is the variance of X?

c) What is the standard deviation of X?

d) What is the probability that X is larger than its expected value?

e) What is the probability that X is > 2?

f) What is the probability that X is > 4?

g) What is the probability that X > 4 given that X > 2?

h) Calculate the 70th percentile of X

Solutions

Expert Solution

NOTE:: * I HOPE YOUR HAPPY WITH MY ANSWER......**PLEASE SUPPORT ME WITH YOUR RATING

***PLEASE GIVE ME "LIKE"....ITS VERY IMPORTANT FOR ME NOW......PLEASE SUPPORT ME .......THANK YOU


Related Solutions

Here is another infectious disease model. Once a person becomes infected, the time X, in days,...
Here is another infectious disease model. Once a person becomes infected, the time X, in days, until the person becomes infectious (can pass on the disease) can be modeled as a Weibull random variable with density function    f(x,α,β) = (α/βα)xα−1e−(x/β)α for 0 ≤ x ≤ ∞ and 0 otherwise with α = 3.7 and β = 7.1 α is the shape parameter and β is the scale parameter. Hint: Solve this with the built-in R functions for the Weibull...
Here is another infectious disease model. Once a person becomes infected, the time X, in days,...
Here is another infectious disease model. Once a person becomes infected, the time X, in days, until the person becomes infectious (can pass on the disease) can be modeled as a Weibull random variable with density function f(x,α,β) = α βα xα−1e−(x/β)α for 0 ≤ x ≤ ∞ and 0 otherwise with α = 3.7 and β = 7.1 α is the shape parameter and β is the scale parameter. Hint: Solve this with the built-in R functions for the...
Once an individual has been infected with a certain disease, let X represent the time (days)...
Once an individual has been infected with a certain disease, let X represent the time (days) that elapses before the individual becomes infectious. An article proposes a Weibull distribution with α = 2.6, β = 1.1, and γ = 0.5. [Hint: The two-parameter Weibull distribution can be generalized by introducing a third parameter γ, called a threshold or location parameter: replace x in the equation below, f(x; α, β) = α βα xα − 1e−(x/β)α x ≥ 0 0 x...
Once an individual has been infected with a certain disease, let X represent the time (days)...
Once an individual has been infected with a certain disease, let X represent the time (days) that elapses before the individual becomes infectious. The article “The Probability of Containment for Multitype Branching Process Models for Emerging Epidemics” (J. of Applied Probability, 2011: 173-188) proposes a Weibull distribution with alpha = 2.2, beta = 1.1, and gamma = 0.5 a. Calculate P(1 < X < 2). b. Calculate P(X > 1.5). c. What is the 90th percentile of the distribution? d....
In a population of 200,000 people, 40,000 are infected with a virus. After a person becomes...
In a population of 200,000 people, 40,000 are infected with a virus. After a person becomes infected and then recovers, the person is immune (cannot become infected again). Of the people who are infected, 5% will die each year and the others will recover. Of the people who have never been infected, 35% will become infected each year. How many people will be infected in 4 years? (Round your answer to the nearest whole number.) ________ people
If person is receiving an anticoagulant, such as heparin for 7 days due to heart disease...
If person is receiving an anticoagulant, such as heparin for 7 days due to heart disease complicated by acute myocardial infarction what changes in his coagulation process can be expected? What factor will be inhibited
What type of immunity occurs when a person has an infectious, communicable disease like measles? a....
What type of immunity occurs when a person has an infectious, communicable disease like measles? a. Adaptive immunity b. Passive natural immunity c. Active natural immunity d. Active artificial immune
Here is the probability model for the blood type of a randomly chosen person in the...
Here is the probability model for the blood type of a randomly chosen person in the United States. Blood type O A B AB Probability 0.52 0.19 0.06 0.23 What is the probability that a randomly chosen American does not have type O blood? % Round to the nearest 0.01%
Here is the probability model for the blood type of a randomly chosen person in the...
Here is the probability model for the blood type of a randomly chosen person in the United States. Blood Type O A B AB Probability 0.31 0.34 0.12 ? (a) What is the probability that a randomly chosen American has type AB blood? Please use 2 decimal places. (b) Maria has type B blood. She can safely receive blood transfusions from people with blood types O and B. What is the probability that a randomly chosen American can donate blood...
Describe one time you successfully persuaded another person (or people) or a time you failed to...
Describe one time you successfully persuaded another person (or people) or a time you failed to persuade another person (or people). Explain why you think you were/were not successful using the elements of persuasion. You must mention at least one element of source characteristics, one element of message characteristics, and one element of audience characteristics. Finally, given what we learned in our persuasion, is there anything you would have changed about your persuasive message (i.e., something about the source, the...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT