Friday

April 17, 2015

April 17, 2015

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

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).

- statistics -
**Damon**, Wednesday, January 23, 2008 at 7:13pma. agree

b The first term in the denominator is those who got the incentive and completed the survey.

The second term in the denominator is those who completed the survey without the incentive.

The sum is all those who completed the survey, which is what you are looking for.

**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...

Survey Assignment - I have an assignment for school to create a survey. Please ...

Math - In a survey of 300 college graduates, 58% reported that they entered a ...

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 ...