To determine whether or not they have a certain disease, 80
people are to have their blood tested. However, rather than testing
each individual separately, it has been decided first to group the
people in groups of 10. The blood samples of the 10 people in each
group will be pooled and analyzed together. If the test is
negative. one test will suffice for the 10 people (we are assuming
that the pooled test will be positive if and only if at least one
person in the pool has the disease); whereas, if the test is
positive each of the 10 people will also be individually tested
and, in all, 11 tests will be made on this group.
Assume the probability that a person has the disease is 0.08 for
all people, independently of each other.
Compute the expected number of tests necessary for each
group.
Expected number for each group:
1)
probability one test will suffice P(X=1) =P(none of 10 have disease ) =(1-0.08)10 =0.434388
P(X=11) =1-0.434388 =0.565612
expected number of tests E(x)=1*0.434388+11*0.565612 =6.656115
To determine whether or not they have a certain disease, 80 people are to have their...
It’s known that 2 % of people in a certain population have the disease. A blood test gives a positive result (indicating the presence of disease) for 95% of people who have the disease, and it is also positive for 3% of healthy people. One person is tested and the test gives positive result. a. If the test result is positive for the person, then the probability that this person actually has a disease is _________ b. If the test...
The proportion of people in a given community who have a certain disease is 0.005. A test is available to diagnose the disease. If a person has the disease, the probability that the test will produce a positive signal is 0.99. If a person does not have the disease, the probability that the test will produce a positive signal is 0.01 a. If a person tests positive, what is the probability that the person has the disease? b. If a...
The proportion of people in a given community who have a certain disease is 0.005. A test is available to diagnose the disease. If a person has the disease, the probability that the test will produce a positive signal is 0.96. If a person does not have the disease, the probability that the test will produce a positive signal is 0.04. 1. If a man tests negative, what is the probability that he actually has the disease? 2. For many...
A medical test is not completely accurate. When people who have a certain disease are tested, 90% of them have a "positive" reaction. But 5% of people without the disease also have a "positive" reaction. In a certain city, 20% of the population have the disease. A person from this city is chosen at random and tested; if the reaction is "positive," what is the probability the person has the disease
In this problem, your goal is to identify who among a group of people has a certain disease. You collect a blood sample from each of the people in the group, and label them 1 through n. Suppose that you know in advance that exactly one person is infected with the disease, and you must identify who that person is by performing blood tests. In a single blood test, you can specify any subset of the samples, combine a drop...
3. Assume 6% of people have a certain disease. A test gives correct diagnosis with probability 0.85 i.e. if the person is sick, the test will be positive with probability 0.85, but if the person is not sick, the test will be positive with probability 0.15. A random person from the population has tested positive for the disease. What is the probability that he is actually sick? Part 2. Random Variables
One percent of all individuals in a certain population are carriers of a particular disease. A diagnostic test for this disease has a 95% detection rate for carriers and a 4% detection rate for non-carriers. Suppose the test for this is applied independently to two different blood samples from the same randomly selected individual. Hint: Use Notation A= {no disease} A'={disease} B1= {1st test positive} B2={2nd test positive} a) What is the probability that the first test is positive? b)...
probabilities I know from given problem:
.99 have disease AND Test + therefore...
.01 have disease AND Test -
.02 do not have disease AND Test + therefore...
.98 do not have disease AND Test -
.10 of TOTAL population HAVE Disease
therefore...
.90 of TOTAL population DO NOT HAVE Disease.
what I thought I would have to do to get what is being
asked is P(have disease | tests +) = P(Have disease AND Test +) /
P(test +)...
In a laboratory, blood test is 95% effective in detecting a certain disease, when it is, in fact, present. However, the test also yields a false positive (test is positive but patient does not have the disease) result for 1% of the healthy people tested. 0.5% of the population actually has the disease. Given this information, calculate the following probabilities: The probability that the test is positive. Given a negative result, the probability that the person does not have the...
Question 10: (10 marks) blood test is 95 percent effective in detecting a certain disease when it is, in fact, also yields a "false positive" result for 10 percent of the healthy persons A laboratory present. However, the test tested. (That is, if a healthy person is tested, then, with probability 0.10, the test result will imply he or she has the disease.) If 0.7 percent of the population actually has the disease, what is the probability a person has...