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## #1 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-05 06:37:03

Ok I used the diagram.  I never know when to use which formula!!! I'll just be happy to pass this class, it's so frustrating.  Wish my mind worked like yours!!

## #2 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-05 06:31:41

4th one with tree diagram

## #3 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-05 06:18:59

6/16=.38

6 possible outcomes 16 total outcomes is how I figured it.  .38 is one of the answer choices.

## #4 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-05 03:59:29

.38 is what I got  Thanks

## #5 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-05 03:50:05

I get 16 using the tree diagram

I got m=10

## #7 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-02 15:15:41

I haven't forgotten about you just been working on another class, will be back tomorrow.  Thanks for all your help.

## #8 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-01 17:30:45

bob bundy wrote:

You don't need 'combinations at all.

So if there are 20 tickets in a hat and you have just one, what is the probability you'll win?

That'll be 1/20

Let's say that happens.

Now you discover you have a second ticket.

What's the probability that it gets chosen too.

Only 19 tickets left and you have one more ticket to check so that'll be

1/19

Now, once again multiply the answers, as you want both events to occur.

So 1/20 times 1/19

Now for question 3.

Would you like a quick reminder of normal distribution theory?  I've got my diagrams all lined up and ready to roll.

Bob

Still working on #2 I'm unsure of answer now.

Yes please for question 3 a reminder of normal dustribution

## #9 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-01 11:40:46

I am incorrect 1/380 is correct

## #10 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-01 11:20:16

Sorry I'm in class. I don't have my notes with me. Will get back to you

## #11 Re: Help Me ! » Probability and sample space -A few more questions » 2012-10-01 07:41:33

Sorry for the poor wording, it is exactly how the question is typed on the study guide.  I came up with 20C2 = 1 in 190 chance.  Is that correct?

## #13 Help Me ! » Probability and sample space -A few more questions » 2012-10-01 03:20:13

Skyblast72
Replies: 33

1)
A group of six children are choosing colored pencils to draw a picture.  Each child is allowed to select one color.  The available colors are green, red, and blue.  If the second child refuses to use red pencils, and the third child refuses to use blue pencils, then how many ways are there for the children to choose pencils? Assume there are 12 pencils for each color and different children are allowed to choose the same color.

2)
If 20 tickets are sold and two (2) prizes ar to be awarded, find the probability that one (1) person will win both prizes if that person buys exactly two (2) tickets.

3)
X is a normally distributed random variable with a standard deviation of 4.00. Find the mean of x if 12.71% of the area under the distribution curve lies to the right of 14.56.  *Please note-I can't get the curve on here, so if you can't help on this one its ok.  The answer choices are 13.3, 11.3, 10.0, and 9.5 (wasn't sure if that would help or not). I understand if there is not enough information to answer this.

4)
A school club consist of 20 male students and 15 female students.  If 4 students are selected to represent the club in the student government, what is the probability 2 will be female and 2 will be male?

Anything you guys could help with would be great.  Thank you

## #14 Re: Help Me ! » Probability of guessing questions on a test » 2012-10-01 00:25:46

THANK YOU!! I see where I messed up now.

## #15 Help Me ! » Probability of guessing questions on a test » 2012-09-30 14:44:24

Skyblast72
Replies: 3

Probability question:

A student takes a 19-question, multiple choice exam with three choices for each question and guesses on each question.  Find the probability of guessing exactly 8 out of 19 correctly.

I used 19C8  so n=19 x =8 p=.33 and q=.67 but I can't come up with any of the answers that are on my homework.

I am a beginning statistics/probability student.  Showing your work would be helpful to me so I can learn how to do this stuff.  Thanks for any help you are able to give, I appreciate it!

## #16 Introductions » Intro » 2012-09-30 14:34:30

Skyblast72
Replies: 5

Hello I am new to the forum.  I am looking for assistance with statistics and probability homework.  Glad I found you!!