Question

A doctor knows that the disease meningitis causes the patient to have a stiff neck 50...

A doctor knows that the disease meningitis causes the patient to have a stiff neck 50 % of the time. The doctor also knows that the probability that the patient has meningitis is 1 in 50,000. And the probability that any patient has stiff neck is 1 in 20. Find the probability that a patient with the stiff neck has meningitis. P(stiff_neck|meningitis) = 0.5 P(meningitis) = 1/50,000 P(stiff_neck) = 1/20 P(meningitis|stiff_neck) =?

Homework Answers

Answer #1

Given:

P(stiff_neck|meningitis) = 0.5

P(meningitis) = 1/50,000

P(stiff_neck) = 1/20

To find:

P(meningitis|stiff_neck) = P(meningitis and stiff_neck)/P(stiff_neck)

calculations:

P(stiff_neck|meningitis) = P(meningitis and stiff_neck)/P(meningitis)

So, P(meningitis and stiff_neck) = P(stiff_neck|meningitis) * P(meningitis) = 0.5*1/50000 = 1*10-5 = 0.00001

Therefore,

P(meningitis|stiff_neck) = P(meningitis and stiff_neck)/P(stiff_neck) = 0.00001/(1/20) = 20*0.00001 = 0.0002

P(meningitis|stiff_neck) = 0.0002

Please rate my answer and comment for doubt.

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Microbiology Meningitis Patient B: Alice Chen, a 6-year-old female, presented to the emergency department with a...
Microbiology Meningitis Patient B: Alice Chen, a 6-year-old female, presented to the emergency department with a 4-day history of worsening headache and a rash on her trunk. Her mother mentioned that over-the-counter medications had no effect on her headache. Alice mentioned that the bright lights of the examination room hurt her eyes and she stated that her “head hurts all over.” She also had difficulty trying to move her neck. A physical test revealed some vesicular lesions on her hands...
A hospital is testing patients for a certain disease. If a patient has the disease, the...
A hospital is testing patients for a certain disease. If a patient has the disease, the test is designed to return a "positive" result. If a patient does not have the disease, the test should return a "negative" result. No test is perfect though. 90% of patients who have the disease will test positive. 10% of patients who don’t have the disease will also test positive. 20% of the population in question has the disease. If a random patient tests...
A patient has been diagnosed with a rare disease that causes the Loop of Henle to...
A patient has been diagnosed with a rare disease that causes the Loop of Henle to shrink. The Loop of Henle begins to shrink at the age of 20 and by the time the person is 40 years old, the Loop of Henle no longer exists. This patient is 28 years old and the Loop of Henle has shrunk quite a bit (about 47% of its original size). Question 4. Explain what would happen to the function of the kidney...
Most medical tests used today have about a 5% false positive rate, which some doctors will...
Most medical tests used today have about a 5% false positive rate, which some doctors will take to mean that if a patient’s test comes back positive, that the patient has a 95% chance of having the disease. A 95% chance is very high, and so the doctor will assume that the patient has the disease and will start an aggressive and potentially dangerous course of treatment. For your first problem, you will show that, for rare diseases, this common...
Mr. Smith goes to his doctor and is told that he just tested positive for some...
Mr. Smith goes to his doctor and is told that he just tested positive for some fatal and rapidly progressing disease. Patients with this disease have a life expectancy exponentially distributed with mean 1 year. Patients of Mr. Smith's age without this disease have a life expectancy exponentially distributed with mean 20 years. 0.1% of the population (i.e., one person in a thousand) suffers from this disease. There is no known treatment that can alter its progression. This test (like...
test for a certain disease is found to be 95% accurate, meaning that it will correctly...
test for a certain disease is found to be 95% accurate, meaning that it will correctly diagnose the disease in 95 out of 100 people who have the ailment. The test is also 95% accurate for a negative result, meaning that it will correctly exclude the disease in 95 out of 100 people who do not have the ailment. For a certain segment of the population, the incidence of the disease is 4%. (1) If a person tests positive, find...
1) Let D = 1 denote the event that an adult male has a particular disease....
1) Let D = 1 denote the event that an adult male has a particular disease. In the population, it is known that the probability of having this disease is 20 percent, i.e.,Pr(D = 1) = :2 Now, suppose that an adult male has a son. Unlike the father's birth, new health policy now requires that all newborn males are tested for the disease. Suppose that a particular adult male's son is tested, and is confirmed not to carry this...
Retinitis pigmentosa is a genetic disease that causes the breakdown and loss of retinal cells. Retinitis...
Retinitis pigmentosa is a genetic disease that causes the breakdown and loss of retinal cells. Retinitis pigmentosa often starts with decreased night vision and will progress to blindness as retinal cells die. Several genes have been linked to Retinitis pigmentosa, one of which is GADD. Mice lacking GADD (these mice were experimentally created so that the GADD region of the genome was deleted) have increased expression of non-retinal genes in retinal cells. In other words, in these mutant mice, genes...
Retinitis pigmentosa is a genetic disease that causes the breakdown and loss of retinal cells. Retinitis...
Retinitis pigmentosa is a genetic disease that causes the breakdown and loss of retinal cells. Retinitis pigmentosa often starts with decreased night vision and will progress to blindness as retinal cells die. Several genes have been linked to Retinitis pigmentosa, one of which is GADD. Mice lacking GADD (these mice were experimentally created so that the GADD region of the genome was deleted) have increased expression of non-retinal genes in retinal cells. In other words, in these mutant mice, genes...
Suppose that we identify 130 women 50 to 54 years of age who have both a...
Suppose that we identify 130 women 50 to 54 years of age who have both a mother and a sister with a history of breast cancer. 16 of these women themselves have developed breast cancer at some time in their lives. If we assume that the proportion of breast cancer cases in women whose mothers have had breast cancer is 8%, does having a sister with the disease increase the risk? Find the p-value. Problem #1(a): p-value (correct to 4...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT