Exercise 14

A fitness center coach kept track over the last year of whether members stretched before they exercised, and whether or not they sustained an injury. Among the 400 members, 322 stretched before they exercised, 327 did not sustain an injury, and 270 both stretched and did not sustain an injury.

1. Create a contingency table for the information.

   	Injury	No Injury	Total
   Stretched
   Not Stretched
   Total

2. What is the probability that a member sustained an injury?

3. What is the probability that a member sustained an injury and did not stretch?

4. What is the probability that a member stretched or did not sustain an injury?

5. What is the probability that a member sustained an injury given they stretched?

6. What is the probability that a member sustained an injury given they did not stretch?

7. Does it appear that sustaining an injury depends on whether the member stretches before exercising? Or are they independent? Use probability to support your claim.