For a randomly selected person, what is the probability the person participates

Question

For a randomly selected person, what is the probability the person participates in exercise walking (to 2 decimals)?

Suppose you just happen to see an exercise walker going by. What is the probability the walker is a woman (to 2 decimals)?


What is the probability the walker is a man (to 2 decimals)?

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The National Sporting Goods Association conducted a survey of persons 7 years of age or older about participation in sports activities (Statistical Abstract of the United States: 2002). The total population in this age group was reported at 248.5 million, with 120.9 million male and 127.6 million female. The number of participants for the top five sports activities appears here.
Participants (millions) Activity Male Female Bicycle riding 20.7 22.5 Camping 24.1 25.8 Exercise walking 30.2 59.2 Exercising with equipment 18.9 25.9 Swimming 24.9 35.9

For a randomly selected female, estimate the probability of participation in each of the sports activities (to 2 decimals). Note that the probabilities do not sum to 1 because of participation in more than one sports activity.
Bicycle riding Camping Exercise walking Exercising with equipment Swimming

For a randomly selected male, estimate the probability of participation in each of the sports activities (to 2 decimals). Note that the probabilities do not sum to 1 because of participation in more than one sports activity.
Bicycle riding Camping Exercise walking Exercising with equipment Swimming

For a randomly selected person, what is the probability the person participates in exercise walking (to 2 decimals)?

Suppose you just happen to see an exercise walker going by. What is the probability the walker is a woman (to 2 decimals)?


What is the probability the walker is a man (to 2 decimals)?

Explanation / Answer

a)

P( Walking) = ( 0.249793 * 120.9/248.5+ 0.46395* 127.6/248.5) = 0.35975

P(Man) = 0.249793 * 120.9/248.5 /  0.35975 = 0.3378

P( Female) = 1-P( Man) = 1-0.3378 = 0.6622

Probability Male Female Bicycle riding 0.171216 0.176332 Camping 0.199338 0.202194 Exercise walking 0.249793 0.46395 Exercising with equipment 0.156328 0.202978 Swimming 0.205955 0.281348

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