4.121 Trail Users survey of San Jose\'s off-street bicycle and pedestrian trail

Question

4.121 Trail Users survey of San Jose's off-street bicycle and pedestrian trail users, According to Trail Count, the annual approximately 24% use trails daily, 15 Suppose 12% use trails daily and exercise, and 8% use trails daily for commuting. Suppose a trail user is randomly selected. a. Given that the person uses trails daily, what is the probability that he uses the trails for exercise? b. Given that the person uses trails daily, what is the probability that she uses the trails for commuting? c. If the person uses trails daily, what is the probability that he does not use the trial for commuting?

Explanation / Answer

a) P(uses trails for excercise|use trails) =P(use trails and excercise)/P(use trails) =0.12/0.24 =1/2 =0.5

b) P(uses trails for commuting|use trails)=P(use trails and commuting)/P(use trails)=0.08/0.24 =1/3=0.33

c)P(not using trail for commuting|use trails) =1-0.08/0.24 =2/3 =0.67

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.