Suppose there is a 34% chance that a risky stock investment will end up in total loss of your investment. Because the rewards are so high, you decide to invest in three independent risky stocks. Find the probability that AT LEAST on of your three stocks becomes a total loss.

2. This is a very common question variety. You must learn to recognize them.

Pr(at least one) = 1 - Pr(none)

3. I still don't get it...

4. Originally Posted by ubamel
Suppose there is a 34% chance that a risky stock investment will end up in total loss of your investment. Because the rewards are so high, you decide to invest in three independent risky stocks. Find the probability that AT LEAST on of your three stocks becomes a total loss.

Third prong: Going from what TKH has said, $\Pr(X > 0) = 1 - \Pr(X = 0)$.

6. Originally Posted by ubamel
Have you been taught the binomial distribution?

7. Originally Posted by ubamel
I still don't get it...
You are given the independence of the three stocks.

Pr(all three fail) = Pr(#1 Failing)*Pr(#2 Failing)*Pr(#3 Failing)

You're not going to make me do all the work, are you?

8. Hhaha, again.. I'm sorry, but yes, I would love it if you do all the work. PLEASe

9. Too bad you won't learn anything.

I've broken it down to simply filling in the blanks. Have you been attending class and reading the required materials?

10. YES!!! I GO TO EVERY CLASS and have my book and all my notes in front of me. I have a hard time with math, I am an art major and I know this is ridiculous. I'm sorry. I tried taking .34 x .34 X .34

The anwser is 0.7125, but I cannot get it and its driving me nuts.

11. Art? Good luck with that. My eldest son just went to the Art Institute of Pittsburgh. It turns out he has some talent. He's related to me, but this is NOT evidence.

If the probability of any of the stocks failing is 0.34, then the probability of all three failing is 0.34*0.34*0.34 = 0.039304, but that is not what we seek.

The probabilitiy of AT LEAST ONE failing is Unity (1) less the probablity of NONE failing. Thus,

1) If Pr(one failing) = 0.34
2) then Pr(one succeeding) = 1 - 0.34 = 0.66
3) Pr(all three succeeding) = 0.66*0.66*0.66 = 0.287496 <== We need the independence assumption for this step.
4) Pr(at least one failing) = 1 - 0.287496 = 0.712504

It takes a very careful reading of the problem. Continue to attend class. Don't be afraid to ask questions. Your professors and teachers want you to understand.

12. You have helped me tremendously, I really appreciate it. Thank you so very much. I will b back to this forum if you don't mind. I will take your advise and ask questions, I just feel like the whole class thinks I'm taking up time.
Erica

13. It is likely the case that your questions are also the questions of others. You are saving other students the trouble of asking. Go for it.

If your professor or teacher is worth his/her salt, said professional educator will be able to judge if you are taking up too much time or if you are holding back the rest of the class. Let the professional educator judge this. Don't let others make the call. Until the professional educator asks you privately to back down a little (probably with a suggestion of turoring, other extra help, or perhaps changing your registration), don't quit asking. Even after such a suggestion, don't be discouraged. Realize you are under professional care and that correct things are happening.