The reliability of a Covid-19 test is specified as follows:
Of people having Covid-19 , 90% of the test detect the disease but 10% go undetected. Of people free
of Covid-19 , 99% of the test are judged Covid-19 negative but 1% are diagnosed as showing Covid-19
positive .
From a large population of which only 0.1% have Covid-19 , one person is selected at random, given
the Covid-19 test and Pathologist reports him/her as Covid-19 positive.
Based on the above information , answer the following questions:
(i) What is the probability of the person to be tested as Covid-19 positive given that he is actually
having Covid-19 ?
(a) 0.001 (b) 0.1 (c)0.8 (d) 0.9
please explain how the answer came...I will surely make you brain list !!
solve it !!!
Answers
Answer:
The reliability of a Covid-19 test is specified as follows:
Of people having Covid-19 , 90% of the test detect the disease but 10% go undetected. Of people free
of Covid-19 , 99% of the test are judged Covid-19 negative but 1% are diagnosed as showing Covid-19
positive .
From a large population of which only 0.1% have Covid-19 , one person is selected at random, given
the Covid-19 test and Pathologist reports him/her as Covid-19 positive.
Based on the above information , answer the following questions:
(i) What is the probability of the person to be tested as Covid-19 positive given that he is actually
having Covid-19 ?
(a) 0.001 (b) 0.1 (c)0.8 (d) 0.9
(ii) What is the probability that the person is actually not having Covid-19 ?
(a) 0.998 (b) 0.999 (c) 0.001 (d)0.111
(iii) What is the probability that the person selected will be diagnosed as Covid-19 positive ?
(a) 0.1089 (b) 0.01089 (c) 0.0189 (d) 0.189
(iv) What is the probability that the person is actually having Covid-19 given that he is tested as
Covid-19 positive ?
(a) 0.83 (b)0.0803 (c)0.083 (d) 0.089