tag:blogger.com,1999:blog-16201792.comments2008-04-20T18:14:39.772-04:00Linner StatisticsMrs.Lhttp://www.blogger.com/profile/15241425636989933131noreply@blogger.comBlogger270125tag:blogger.com,1999:blog-16201792.post-72125141561635310392008-04-20T18:14:00.000-04:002008-04-20T18:14:00.000-04:00Tuesday would be OK. . .Tuesday would be OK. . .Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-78022533047051683272008-04-20T16:13:00.000-04:002008-04-20T16:13:00.000-04:00i signed up to take the practice test tomorrow aft...i signed up to take the practice test tomorrow after school, but i just realized that i have my last track practice/meeting tomorrow right after school. when i signed up, i was thinking that i wouldn't have track at all this week because we just had our last meet. i'm really sorry - i made a mistake. is there any way i can change to a different day?emilyhttps://www.blogger.com/profile/10298441469405829402noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-38275154372136972442008-02-27T17:31:00.000-05:002008-02-27T17:31:00.000-05:00You'll probably notice that the section of the tex...You'll probably notice that the section of the text discussing Type I and Type II errors is filled with "accept" notation--even the two-way table! Rest assured that YMS3 (the new edition with Daren Starnes) consistently uses FTR. I suspect that Moore was behind the "filthy" language because even YMS2 used the dreaded a-word.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-80567620583768675522008-02-27T16:37:00.000-05:002008-02-27T16:37:00.000-05:00Warning: The text book authors need to be punished...Warning: The text book authors need to be punished. The answer in the back of the book for number 67 says "We accept the null hypothesis if..." =O <BR/>boooderekhttps://www.blogger.com/profile/00752509709364185840noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-3960568764167159512008-02-06T21:53:00.000-05:002008-02-06T21:53:00.000-05:00I am working 9.23(dealing with probabilities) and ...I am working 9.23(dealing with probabilities) and I can't remember how to find what it is asking for. It is a great problem to work though and i would recommend it to anyone who is still having trouble with p and p-hat. The page before has formulas like the square root of p times 1-p over n and I think I am supposed to use that but I don't know exactly how.derekhttps://www.blogger.com/profile/00752509709364185840noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-71071892182283964672008-02-06T21:43:00.000-05:002008-02-06T21:43:00.000-05:00Regarding MUST BE and NEEDS TO BE:The Central Limi...Regarding MUST BE and NEEDS TO BE:<BR/><BR/>The Central Limit Theorem only applies under special conditions. <BR/><BR/>The closer your original distribution was to normal to begin with, the lower the sample size will be for it to apply. <BR/><BR/>For instance, if the distribution of x is distinctly non-normal (envision the wildest distribution that you can), then the sample size must be really big for you to assume that the sample means are normally-distributed. On the other hand, if the x values are distributed almost normally, then even little samples will have averages that are approximately normal.<BR/><BR/>When I wrote the summaries up, I wrote them from the other perspective (small size NEEDS near-normality, for example) because you are given a sample size and a description of the x distribution, so you have to determine whether the sample is large enough to indicate that the sample means are normally-distributed given the characteristics of the underlying distribution.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-88152215172686539702008-02-06T21:39:00.000-05:002008-02-06T21:39:00.000-05:00very helpful site thanks =]my only comment is that...very helpful site thanks =]my only comment is that it uses variance more than we have and that kind of got in the way but you just have to ignore it.derekhttps://www.blogger.com/profile/00752509709364185840noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-48582353323226989652008-02-06T21:33:00.000-05:002008-02-06T21:33:00.000-05:00Further answers to unposted questions:x-bar is the...Further answers to unposted questions:<BR/><BR/>x-bar is the <B>MEAN </B>of the SAMPLE<BR/>mu is the MEAN of the POPULATION<BR/><BR/>When the sample size is small you CAN'T use normal procedures UNLESS (Case 0)the underlying distribution of x is normal(CLT not required :D) or (Case 1)the distribution is reasonably close to normal (CLT kicks in).Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-80175612359504684142008-02-06T21:05:00.000-05:002008-02-06T21:05:00.000-05:00Here's a site that discusses the CLT and calls it ...Here's a site that discusses the CLT and calls it <I>amazing.</I> I have to agree.<BR/><BR/>[Gaussian means the same as Normal.]<BR/><BR/>http://cs.wellesley.edu/~cs199/lectures/23-std-err-CLT.htmlMrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-91540292772800954632008-02-06T21:02:00.000-05:002008-02-06T21:02:00.000-05:00Re: the CLTHow do you intend to find the probabili...Re: the CLT<BR/><BR/>How do you intend to find the probability that x-bar is greater than 5 if you can't use the normal distribution?<BR/><BR/>Most distributions are NOT normal. It's pretty special that the means (under some conditions) are normally distributed.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-56730947876869647052008-02-06T20:57:00.000-05:002008-02-06T20:57:00.000-05:00You will be using BOTH mu and x-bar in some proble...You will be using BOTH mu and x-bar in some problems, just like you use BOTH p and p-hat in some problems. Mu/x-bar problems concern measures, while p/p-hat problems concern proportions. <BR/><BR/>Do you recall how we drew boxes and ovals around the values of p and p-hat on that one worksheet? Well, identifying the mu and the x-bar is analogous. Mu is the value that describes the entire population. X-bar only describes the sample.<BR/><BR/>Sometimes x-bar is an actual measure, but most of our examples from this chapter just ask hypothetical questions like<I> what would the probability be when. . .</I> Whereas the mean, mu, is the center of our distribution, these values of x-bar become the lower or upper bounds of the region we evaluate for area (probability). This works just like the way p-hat represented the upper or lower bound of the shaded region in the graph! Convert the x-bar to a z-value as we did in class, and find the associated probability.<BR/><BR/>Are you a master of the probability statements??<BR/><BR/>P(statistic < number) = <BR/>P( (stat - param)/std dev of stat < <BR/> (number - param)/std dev of stat)<BR/><BR/><BR/>For instance:<BR/>Let x be normally-distributed with a mean of 2 and a std dev of 21. What is the probability that a sample of size 49 would have an average greater than 5?<BR/><BR/>[Note that sigma of x-bar is 21/sqrt 49 = 21/7 = 3.]<BR/><BR/>P(x-bar > 5) = P((x-bar - mu)/sigma of x-bar > (5 - 2)/3)<BR/>= P(z > 1) = .1587<BR/><BR/>Readers: Please put parts of this message into your own words and respond to this blog so we can make sure that we understand. Thanks!Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-41631945990760247102008-02-06T20:50:00.000-05:002008-02-06T20:50:00.000-05:00And I still don't get why the Central Limit Theore...And I still don't get why the Central Limit Theorem is significant. I know it helps prove that it is normally distributed. Does that help prove the accuracy of my answer? And in Case 1 and 2 on the CLT sheet, what does it mean by "must be" and "needs to be"?MrFantasianhttps://www.blogger.com/profile/01750777925272408233noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-55019586732289317882008-02-06T20:20:00.000-05:002008-02-06T20:20:00.000-05:00How would I know whether to use x bar or mu in cer...How would I know whether to use x bar or mu in certain problems? Is it within the context of the problem and if they are, what are tehy?MrFantasianhttps://www.blogger.com/profile/01750777925272408233noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-33227145897106555272008-01-30T22:41:00.000-05:002008-01-30T22:41:00.000-05:00Calling all stat studs! Can anyone else help with ...Calling all stat studs! Can anyone else help with this problem? I don't have a copy of the problem at home, so the best I can do is answer questions before school.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-11659277597284825842008-01-30T21:07:00.000-05:002008-01-30T21:07:00.000-05:00the wording in problem number 11 is a bit confusin...the wording in problem number 11 is a bit confusing to me. i would greatly appreciate it if you could help point me in the direction of what it is asking for...derekhttps://www.blogger.com/profile/00752509709364185840noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-66723897601893160372008-01-27T18:56:00.000-05:002008-01-27T18:56:00.000-05:00Pam C,You made my day! Please come back and visit ...Pam C,<BR/>You made my day! Please come back and visit my classes sometime.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-4925050461214122132008-01-27T16:30:00.000-05:002008-01-27T16:30:00.000-05:00All the work tht was already assigned, including a...All the work tht was already assigned, including a complete, legible draft of the classwork (the answers to the exam problem about depth of the refracting layer). Answers must be correct and complete.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-3781558137355803132007-12-19T15:48:00.000-05:002007-12-19T15:48:00.000-05:00hey guys! There's a group meeting at Mrs. L's Cici...hey guys! There's a group meeting at Mrs. L's Cici's for dinner tonight (around 6:00pm)...bring paper, pencil, book, calculator....(oh yeah!) and your brain!Jordan OMhttps://www.blogger.com/profile/02349172673383810938noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-78279668095310883532007-12-11T20:01:00.000-05:002007-12-11T20:01:00.000-05:00RR- That question should be handled in person.RR- That question should be handled in person.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-6904868758420035772007-12-05T23:07:00.000-05:002007-12-05T23:07:00.000-05:00Disjoint means that there is no overlap in the eve...Disjoint means that there is no overlap in the events. It is the same as mutually exclusive. For instance, you cannot get heads and tails on the same flip of a coin, or odd and two on one roll of a die. These are disjoint events.<BR/><BR/>The P(A&B)/P(A) is the conditional probability of B given that A happens. Many of our recent homework problems were good examples of this, for instance the probability that a randomly-selected working person was a woman was 46% (P(W)). The probability that a randomly-selected working woman was a manager was 32% (P(M given W)). <BR/><BR/>The probability that a randomly-selected working person is a woman AND a manager is P(W & M) = .46 times .32. <BR/><BR/>Similarly, the probability that the randomly-selected point in the 1 x 1 square falls in the cross-hatched area was 1/8 (P(y<.5 & y>x)). <BR/>The probability that a point falls in the upper-left triangle within the box was 1/2 (P(y>x)). <BR/>The probability that the point falls in the cross-hatched area GIVEN that it fell in the upper triangle is (1/8) / (1/2) = 1/4 (P(y<.5 & y>x)/P(y>x) = P(y<.5 given y > x)).<BR/><BR/>This is a very important part of the chapter.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-8189739572415373142007-12-05T20:07:00.000-05:002007-12-05T20:07:00.000-05:00I was wondering what the difference between disjoi...I was wondering what the difference between disjointed and independent were, and do you think you might be able to explain the P(A&B)/P(A) thing that we've talked about in class? I don't really understand it all that well.<BR/><BR/><BR/>Evan 1stEvan D.https://www.blogger.com/profile/09518817908156597640noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-77768201811395594032007-11-25T13:20:00.000-05:002007-11-25T13:20:00.000-05:00State of Fear is due Thursday, November 29.There a...<I>State of Fear</I> is due Thursday, November 29.<BR/><BR/>There are MANY copies out there on the bookshelves of last year's students if you still haven't borrowed one. A lot of the students' parents also read the book. There should also be copies available at the public library. (It's even available on DVD, but I wouldn't recommend it because you miss out on the graphs.)<BR/><BR/>Please note that while the author seems to be taking a stand on the issue, and was widely reviled in Hollywood for it, his point has to do with HOW and WHY we believe claims, not WHAT we believe. <BR/><BR/>Also, there's some rich information in the Epilogue that I'm sure you won't want to miss. Don't "give it away"!Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-89806147429150612022007-11-25T13:03:00.000-05:002007-11-25T13:03:00.000-05:00when do we have to read state of fear bywhen do we have to read <I>state of fear</I> byemilyhttps://www.blogger.com/profile/10298441469405829402noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-45540845526903674582007-11-19T19:38:00.000-05:002007-11-19T19:38:00.000-05:00Yes, all the listed problems: 9,10,12,13,16This on...Yes, all the listed problems: 9,10,12,13,16<BR/>This only adds 1-2 problems to what you did for HW over the weekend.Mrs.Lhttps://www.blogger.com/profile/15241425636989933131noreply@blogger.comtag:blogger.com,1999:blog-16201792.post-17042474432890854062007-11-19T19:10:00.000-05:002007-11-19T19:10:00.000-05:00im still confused is the hw for tmrw all the menti...im still confused is the hw for tmrw all the mentioned pblms???Keonnie!https://www.blogger.com/profile/12051385988386231801noreply@blogger.com