virgigirlie 0 #1 November 28, 2008 My boyfriend (the English & history teacher) is taking online classes and has to take a statistics class. He's never had any of this before and the last time I had it was 10 or 11 years ago. I've helped him with what I can, but there's stuff I can't touch. Does anybody know anything about chi-squares? I'd never heard of them until he got this assignment and neither of us understand how to do the assignment. Using the attached data, he has to do this assignment: Assume this is a sample of students and that students receive an A grade if their score is 90 or above. Calculate a chi-square test to determine whether girls achieve more A grades than boys in math. Calculate a chi-square test to determine whether girls achieve more A grades than boys in reading. Can someone tell me how to do this??? Please??? You may even get a special reward!"If you can't be a good example, then you'll just have to be a horrible warning." ~Catherine Aird Quote Share this post Link to post Share on other sites
Broke 0 #2 November 28, 2008 I think that question is biased and offensive... why couldn't the boys at least get As in PE... lol I have no clue how to answer your question. Check with his text book ok wikipediaDivot your source for all things Hillbilly. Anvil Brother 84 SCR 14192 Quote Share this post Link to post Share on other sites
gonzalesna 0 #3 November 28, 2008 Quote My boyfriend (the English & history teacher) is taking online classes and has to take a statistics class. He's never had any of this before and the last time I had it was 10 or 11 years ago. I've helped him with what I can, but there's stuff I can't touch. Does anybody know anything about chi-squares? I'd never heard of them until he got this assignment and neither of us understand how to do the assignment. Using the attached data, he has to do this assignment: Assume this is a sample of students and that students receive an A grade if their score is 90 or above. Calculate a chi-square test to determine whether girls achieve more A grades than boys in math. Calculate a chi-square test to determine whether girls achieve more A grades than boys in reading. Can someone tell me how to do this??? Please??? You may even get a special reward! the answers are B, E, E and R... alone, the anwers are woreisthsless, but togheter they''ree great...Some people refrain from beating a dead horse. Personally, I find a myriad of entertainment value when beating it until it becomes a horse-smoothie. Quote Share this post Link to post Share on other sites
LOSTandCRAZY 0 #4 November 28, 2008 Ah, the ol' Probability Theory....... on o' my FAVORITES!!!! Which function? These are the three functions: Probability density function A probability density function of the chi-square distribution is where Γ denotes the Gamma function, which has closed-form values at the half-integers. Cumulative distribution function Its cumulative distribution function is: where γ(k,z) is the lower incomplete Gamma function and P(k,z) is the regularized Gamma function. Tables of this distribution — usually in its cumulative form — are widely available and the function is included in many spreadsheets and all statistical packages. Characteristic function The characteristic function of the Chi-square distribution is Expected value and variance If then E(X) = k Var(X) = 2k Since you're looking for characteristics of males vs. females, the latter applies. I'd use the characteristic value as Male and Female, E(X) = k Then solve for variance : Var(X) = 2k That's a pretty simple function: The solution would be: X (t;k) = (1-2it) (exp)-k/2 Use the formula function inside Excel to compute. Dealing with two charachteristc values, you'd have to sum and average the scores of all males and all females as well, to get a good symmetrical view. God, this isn't rocket science......."Get these balls!" Quote Share this post Link to post Share on other sites
LadiDadi 0 #5 November 28, 2008 I'm not going to do your homework for you. You shouldn't be doing your boyfriend's homework. Besides, I just finished my brother-in-law's algebra homework. You get a link - I don't feel like typing all of the instructions out (they'd have to go in a document because of the special characters and then I'd have to find the special characters and then attached and blah, blah, blah... The best explaination I found is courtesy or the fine folks at St. Benedict's - St. John's University's Physics Department. I married myself a physics major and I can assure you that they are quite useful. The link is http://www.physics.csbsju.edu/stats/chi-square.html And, yes, there is a link on that page to a calculator but that's cheating. The giant equation looks scary and intimidating at first but it's actually a very simple one. Good luck!If you can't laugh at yourself, I'll be happy to do it for you. **************************** Be like the cupcake and suck it up. Quote Share this post Link to post Share on other sites
gonzalesna 0 #6 November 28, 2008 QuoteI'm not going to do your homework for you. You shouldn't be doing your boyfriend's homework. Besides, I just finished my brother-in-law's algebra homework. You get a link - I don't feel like typing all of the instructions out (they'd have to go in a document because of the special characters and then I'd have to find the special characters and then attached and blah, blah, blah... The best explaination I found is courtesy or the fine folks at St. Benedict's - St. John's University's Physics Department. I married myself a physics major and I can assure you that they are quite useful. The link is http://www.physics.csbsju.edu/stats/chi-square.html And, yes, there is a link on that page to a calculator but that's cheating. The giant equation looks scary and intimidating at first but it's actually a very simple one. Good luck! i sgtill stay all the worelds prbelms could be slved with a beer in han dfor eeryoneSome people refrain from beating a dead horse. Personally, I find a myriad of entertainment value when beating it until it becomes a horse-smoothie. Quote Share this post Link to post Share on other sites
LOSTandCRAZY 0 #7 November 28, 2008 I've found the best resource for Probability Theory is at the MIT OpenCourseware site here: http://ocw.mit.edu/OcwWeb/Electrical-Engineering-and-Computer-Science/6-050JInformation-and-EntropySpring2003/Units/index.htm You will want to select unit 4: Probability The one I completed was in the Computational Sciences lab, and I found it pretty informational, but not really challenging. And if you read above, I gave you the answer, lol."Get these balls!" Quote Share this post Link to post Share on other sites
gonzalesna 0 #8 November 28, 2008 you dust mede my hed hearut... i need nanother brrr Some people refrain from beating a dead horse. Personally, I find a myriad of entertainment value when beating it until it becomes a horse-smoothie. Quote Share this post Link to post Share on other sites
LOSTandCRAZY 0 #9 November 28, 2008 I think the beer made your head hurt...... You gotta alternate water/beer/water/beer, dude."Get these balls!" Quote Share this post Link to post Share on other sites
gonzalesna 0 #10 November 28, 2008 Quote I think the beer made your head hurt...... You gotta alternate water/beer/water/beer, dude. wareter is au cruatchSome people refrain from beating a dead horse. Personally, I find a myriad of entertainment value when beating it until it becomes a horse-smoothie. Quote Share this post Link to post Share on other sites
LOSTandCRAZY 0 #11 November 28, 2008 Coors Light has definately produced some of my best work....... So I can commiserate. "Get these balls!" Quote Share this post Link to post Share on other sites
virgigirlie 0 #12 November 28, 2008 Yeah!! Thank you all for your help! Homework done! Your rewards are attached below. My boyfriend is eternally grateful. Edited to add: NSFW"If you can't be a good example, then you'll just have to be a horrible warning." ~Catherine Aird Quote Share this post Link to post Share on other sites
gonzalesna 0 #13 November 28, 2008 Quote Coors Light has definately produced some of my best work....... So I can commiserate. i prerefer puderwerser... but her'se to berrSome people refrain from beating a dead horse. Personally, I find a myriad of entertainment value when beating it until it becomes a horse-smoothie. Quote Share this post Link to post Share on other sites
shropshire 0 #14 November 28, 2008 QuoteYeah!! Thank you all for your help! Homework done! Your rewards are attached below. My boyfriend is eternally grateful. I can imagine that those attachments are not exactly safe for work (NSFW) - So I'll pass for now. I don't like my job... but it pays for now. (.)Y(.) Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome Quote Share this post Link to post Share on other sites
LOSTandCRAZY 0 #15 November 28, 2008 Quote Yeah!! Thank you all for your help! Homework done! Your rewards are attached below. My boyfriend is eternally grateful. You're very welcome. If math skills equal titties, I'd be Hugh Heffner. Next time, give me something a little more difficult. (I would have said "harder", but then I would have had to listen to people complain about whether the pun was intended or not!) Numbers are easy. I just wish my wife was so inclined.... "Get these balls!" Quote Share this post Link to post Share on other sites
LOSTandCRAZY 0 #16 November 29, 2008 And can you THANK me again, for helping you solve the less-intellectual of all probability-related questions, preferrably, with bigger titties? I REALLY like the fact that my intellect outweighed that of virtually every human on this site, but can you PLEASE remind these people that not all of us are true idiots by posting some BREASTS on here???? I mean, Nicole Kidman has better tits than that, and she doesn't even EAT food...... "Get these balls!" Quote Share this post Link to post Share on other sites
