Posted by **stats-help** on Wednesday, January 23, 2008 at 6:52pm.

7.

In a certain survey, 30% of those questioned are given an incentive to complete the survey. Of those who receive incentives, 80% completed the survey. Of those who do not receive incentives, 25% completed the survey.

a. Find the probability of getting incentives for those who completed the survey. Hint: Use Bayes’ Theorem

b. If one questioned subject is selected at random, find the probability that is completed. Hint: The answer is in part a.

I found the part A answer to be 0.578 by using bayes.

(0.8*0.3)/(0.8*0.3 + 0.25*0.7)

but i have no idea on how to find b. I thought it woudl be .8*.25 because .8 completed the survey with incentives and .25 completed survey so the proabiblity would be 1/(.8*.25).

## Answer this Question

## Related Questions

- PSYCHOLOGY - Will someone please point me in the right direction. How would you ...
- PSYCHOLOGY - Will someone please point me in the right direction. How would you ...
- Business Research and writing - Write a short survey (8 to 10 questions) that is...
- Math - In a survey of 300 college graduates, 58% reported that they entered a ...
- Survey Assignment - I have an assignment for school to create a survey. Please ...
- math - There were 25 students who completed a survey. There were 11 boys and 14 ...
- math - There were 29 students who completed a survey. There were 15 boys and 14 ...
- Math HELPPP - In a survey of 2000 adults 50 years and older of whom 40% were ...
- 7th grade - There were 31 students who completed a survey. There were 13 boys ...
- business statistics - A marketing research firm is conducting a survey to ...

More Related Questions