A survey asked a group of 400 people whether or not they were doing daily exercise. The responses by sex and physical activity are as in Table.
A person is randomly selected.
(a) What is the probability that this person is doing daily exercise?
(b) What is the probability that this person is doing daily exercise if we know that this person is a male?
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Table
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Male
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Female
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Daily exercise
|
50
|
61
|
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No daily exercise
|
177
|
112
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