In surveys about sensitive topics, respondents are sometimes given ways to “hide” their answers from the surveyor. In a survey of taxpayers, one of the questions is, “Did you cheat on your taxes?” To answer, the respondent is asked to toss a coin. If it lands heads, the respondent must answer “yes.” If it lands tails, the respondent must answer the question truthfully, either “yes” or “no” (the answer has to be the one that is true). Assume that all respondents follow this procedure, and that for 10% of the respondents the truthful answer is “yes.” Also assume that the result of a respondent’s coin toss is independent of whether or not the respondent cheated on his/her taxes.

Question

In surveys about sensitive topics, respondents are sometimes given ways to “hide” their answers from the surveyor. In a survey of taxpayers, one of the questions is, “Did you cheat on your taxes?” To answer, the respondent is asked to toss a coin. If it lands heads, the respondent must answer “yes.” If it lands tails, the respondent must answer the question truthfully, either “yes” or “no” (the answer has to be the one that is true). Assume that all respondents follow this procedure, and that for 10% of the respondents the truthful answer is “yes.” Also assume that the result of a respondent’s coin toss is independent of whether or not the respondent cheated on his/her taxes.

One of the respondents is picked at random.

Q1 Given that the respondent cheated on his/her taxes, what is the chance that he/she answered “yes”?

Q2 Given that the respondent did not cheat on his/her taxes, what is the chance that he/she answered “yes”?

Q3 Given that the respondent answered “yes,” what is the chance that the respondent cheated on his/her taxes?

Answer 1

So, trying to cheat on your edx exam? You'll only feel bad. Go back to the notes and work it out.

Answer 2

Thks Bob,as soon as you get the answer you can post us how to do it...

Answer 3

Yeah, Bob. Don't be mean.

Anyways, I'm relevantly sure thet the first answer is 100%, and the second one is 50%.

Answer 4

Yeah Bob, this guy probably wants a job deciding whether a drug is safe or not. What harm is there if s/he is totally clueless about probability?

Answer 5

I'm with Bob, the test and the course are very easy. I started it a week ago and I have already gotten a passing grade. If you try hard, you shouldn't have difficulty in passing the course. So just try to follow the Honor Code and do not cheat.

Answer 6

OK but really about part C I'm confused.

I think it should be 25% or 0.25 but it is wrong!!!!

Answer 7

here are:

A=1
B=.5
C, I'm in the process to solve it, Definitely is not 1 or 0

after all, in real life you'll have to prove that you are able solve this kind of problems by yourself, or you better not say that you know probability!

Answer 8

C=0.0909???

Answer 9

So, trying to cheat on your edx exam? You'll only feel bad. Go back to the notes and work it out.

Thks Bob,as soon as you get the answer you can post us how to do it...

Yeah, Bob. Don't be mean.

Yeah Bob, this guy probably wants a job deciding whether a drug is safe or not. What harm is there if s/he is totally clueless about probability?

I'm with Bob, the test and the course are very easy. I started it a week ago and I have already gotten a passing grade. If you try hard, you shouldn't have difficulty in passing the course. So just try to follow the Honor Code and do not cheat.

OK but really about part C I'm confused.

C is 1

here are:

C=0.0909???

C = 0.0909 and 0.6 are wrong