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Statistics... Help!

7. The table below represents the results for a test for a certain disease. Answer the questions that follow.

The individual actually
Has the disease
Yes No
Positive 132 13
Negative 25 130

a) What is the probability of picking someone who has the disease.


b) What is the probability of picking someone who tests negative, given that he/she did not have the disease?

User USeRnAmEhAhAhAhAhA
by
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1 Answer

22 votes
22 votes

Answer:

a) 0.5233 = 52.33% probability of picking someone who has the disease.

b) 0.9091 = 90.91% probability of picking someone who tests negative, given that he/she did not have the disease

Explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

a) What is the probability of picking someone who has the disease.

132 + 25 = 157 people have the disease

132 + 25 + 13 + 130 = 300 people total

157/300 = 0.5233

0.5233 = 52.33% probability of picking someone who has the disease.

b) What is the probability of picking someone who tests negative, given that he/she did not have the disease?

143 people did not have the disease.

130 tested negative. So

130/143 = 0.9091

0.9091 = 90.91% probability of picking someone who tests negative, given that he/she did not have the disease

User Mathias Becher
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