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Five hundred people used a home test for HIV and then all underwent more conclus

ID: 3310039 • Letter: F

Question

Five hundred people used a home test for HIV and then all underwent more conclusive hospital testing. The accuracy of the home test was evidenced in the following table.
HIV Healthy Total
Positive Test 65 34 99
Negative Test 7 494 501
Total 72 528 600
A. What is the predictive value of the test? That is, what is the probability that a person has HIV and tests positive?
B. What is the false - positive rate? That is, what is the probability of testing positive given that the person does not have HIV?
C. What is the sensivity of the test? That is, what is the probability of testing positive given that the person has HIV?
D. What is the specificity of the tests? That is, what is the probability of testing negative given that the person does not have HIV?
Do you believe it is worthwhile for people to continue purchase the home test? Explain using Statistics. Five hundred people used a home test for HIV and then all underwent more conclusive hospital testing. The accuracy of the home test was evidenced in the following table.
HIV Healthy Total
Positive Test 65 34 99
Negative Test 7 494 501
Total 72 528 600
A. What is the predictive value of the test? That is, what is the probability that a person has HIV and tests positive?
B. What is the false - positive rate? That is, what is the probability of testing positive given that the person does not have HIV?
C. What is the sensivity of the test? That is, what is the probability of testing positive given that the person has HIV?
D. What is the specificity of the tests? That is, what is the probability of testing negative given that the person does not have HIV?
Do you believe it is worthwhile for people to continue purchase the home test? Explain using Statistics.
HIV Healthy Total
Positive Test 65 34 99
Negative Test 7 494 501
Total 72 528 600
A. What is the predictive value of the test? That is, what is the probability that a person has HIV and tests positive?
B. What is the false - positive rate? That is, what is the probability of testing positive given that the person does not have HIV?
C. What is the sensivity of the test? That is, what is the probability of testing positive given that the person has HIV?
D. What is the specificity of the tests? That is, what is the probability of testing negative given that the person does not have HIV?
Do you believe it is worthwhile for people to continue purchase the home test? Explain using Statistics. HIV Healthy Total
Positive Test 65 34 99
Negative Test 7 494 501
Total 72 528 600
A. What is the predictive value of the test? That is, what is the probability that a person has HIV and tests positive?
B. What is the false - positive rate? That is, what is the probability of testing positive given that the person does not have HIV?
C. What is the sensivity of the test? That is, what is the probability of testing positive given that the person has HIV?
D. What is the specificity of the tests? That is, what is the probability of testing negative given that the person does not have HIV?
Do you believe it is worthwhile for people to continue purchase the home test? Explain using Statistics.

Explanation / Answer

a) From Table

Probability that a person has the disease given they have received a positive test result = 65/500 = 0.13

Hence, the predictive value of the test is 0.13 or 13%.

(b)

.The probability of testing positive given that the person does not have HIV = 7/72 =0.0972

ence, the sensitivity of the test is 0.0972 or 9.72%

C)

The probability of testing positive given that the person has the disease = 65/72 = 0.9028

Hence, the sensitivity of the test is 0.9028 or 90.28%

(d)

The probability of testing negative given that the person does not have the disease = 34/528 = 0.064

Hence, the specificity of the test is 0.064 or 6.4%.