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1. ### 95% Confidence Intervals

Ok. . . Now to expand from CI's to hypothesis testing. . . I understand that for small n, and data approx. Normal, you use the formula T= (x-bar - mu initial)/(s/ sqr n) Now, what If i have no mu initial given. . . Example- Sample mean= 0.8 St. D= 0.1789 n=6
2. ### 95% Confidence Intervals

Oh that is so easy! I way over thought that. . . Thanks guys
3. ### 95% Confidence Intervals

I was under the impression that 95% C.I requires that the critical value in the error term comes from a t-distribution with 25 degrees of freedom. I was taught in class today that a 25% CI requires that the critical value in the error term comes from a t-distribution with 23 degrees of...
4. ### What is the probability

I have ran thru a couple of other problems that are a lot easier to see if I have improved at all. . . Thought maybe you would enjoy checking over them :-)? 1. A game of Yahtzee, you get 3 rolls of the dice per turn, and you get to choose which ones you re-roll each time. My brother calls me...
5. ### What is the probability

^ and the n would still be 125 since there are 125 students. . .
6. ### What is the probability

Here I was, thinking I was on a roll. . . Ugh. Well, would this involve using the same formula? The: (n/x)p^x(1-p)^n-x the p would still equal 0.05 since its 5%?
7. ### What is the probability

Yes, I see how that works. I can NOT believe I was so easily confused by some basic algebra! AH! I feel quite ridiculous having stumbled through that the way I had. Thank you so much for your support!
8. ### What is the probability

For the question about the friends coming down to attend a football game, I do believe I have to use the equation. . . (n/x)p^x(1-p)^n-x Here, I think, you would use 125 for n (since there are 125 students asked), 4 for x (since there is a total of four tickets needed), and the p would be...
9. ### What is the probability

AH! :-)! (drum roll. . . ) 0 = (-5)(12) + (W)(1) … 60= 1W W= 60 EVEN :-) ! (right*crosses fingers*- third time is a charm???)
10. ### What is the probability

0 = E(x)= (-5)(12/13)+(W)(1/13), so, W = 13W? Meaning -4.6153 should be divided by 13W? And no! I am really trying to learn this. . . I greatly appreciate your help! I am a psychology major with an emphasis with behavior analysis- I never work with stats on my day to day life! But I...

13. ### What is the probability

I do believe that I have an idea as to how to do number 5. E(x)= (amount lossed)(prob. of loss)+(amount gained)(prob. of a win) where x= expected value of the profited?
14. ### What is the probability

ooooh! thank you for your help!
15. ### What is the probability

3. Total amount of defective springs = 1+4+2= 7% If there is 7 percent of the total productive of springs that are defective, shouldn't the chances that a randomly defective spring also be 7%? 4. Dice= numbers 1-6. Here is where i get confused. You could roll a two which could be higher if...
16. ### What is the probability

The number of triples? 125 students? Hm. . . would that be 125/3=41.7?
17. ### What is the probability

2. Both of us have a dice. (1/6 probability of rolling any number on the die) Probability of pulling a red = 5/8 Probability of pulling blue= 3/8 Probability of having the same number OR same color? Same number = (since 1-3 are the only similar numbers) 3/8 Same color= pulling...
18. ### What is the probability

I am really awful at statistics, so I literally have to talk myself thru every step, but that will help everyone identify just what I am doing wrong! 1. So to find the probability that four will go to the game: 1-P(of not getting 4 tickets) ~keeping in mind the 5% chance of an extra...
19. ### What is the probability

Hey guys. I am having some issues understanding how to calculate these. If anyone could help, it would be greatly appreciated. 1. My friends came down to visit and wanted to go to a football game. Tickets were sold out, but I planned on asking my student's in lab throughout the day to see if...