Question

A case in riverhead, new york, nine different crime victims listened to voice recordings of five different men. all nine victims identified the same voice as that of the criminal. if the voice identifications were made by random guesses, find the probability that all nine victims would select the same person. you should enter your answer as a decimal, not as a percent. do not round, as your answer should be a terminating decimal. hint: we are looking for the probability that nine victims randomly picked the same person from a line-up. let's take this question one victim at a time: the first victim doesn't need to pick suspect #1, they could pick any suspect, if they are picking randomly. so what is the probability that the first victim picks someone

Answer 1

the complete question in the attached figure

1) Find the probability that all nine victims would select the same person. You should enter your answer as a decimal, not as a percent. Do not round, as your answer should be a terminating decimal.

P=(1/5)*(1/5)*(1/5)*(1/5)*(1/5)*(1/5)*(1/5)*(1/5)*(1/5)=0.000000512

2) what is the probability that the first victim picks SOMEONE? ANYONE? 

P=(1/5)=0.20  ---------------- > 20%

3) Now let’s look at victim #2. What is the probability that they pick the same person as victim #1?

P=(1/5)*(1/5)=0.04 --------------> 4%

4) Now let’s look at victim #3. What is the probability that they pick the same person as victim #1?

P=(1/5)*(1/5)*(1/5)=0.008 --------------> 0.8%

5) Now let's look at victim #9. What is the probability that they pick the same person as victim #1? 

P=(1/5)*(1/5)*(1/5)*(1/5)*(1/5)*(1/5)*(1/5)*(1/5)*(1/5)=0.000000512

6) Once you find all those probabilities, what rule would apply?

the probability is given by (1/5)^n

n=number of victims that pick the same person---------> in this problem = 9

P=(1/5)^9= 0.000000512