<p>Is ANOVA on the the test?</p>
<p>What raw score would I need to guarantee a 5?
Also, can someone summarize all the inference tests? My teacher never taught us how to do them.</p>
<p>bellcurves idk how you can pull off a 5 without knowing inference tests. I have a bad teacher so i can’t help you with the later part of your question maybe someone else can.</p>
<p>^^
I read the textbook myself, just need a good summary.</p>
<p>The problem is that the AP Stat exam is relatively new that there isn’t an exact percentage and data such as that tabulated fully as compared to older tests such as APUSH which basically tell you that you need this many points out of this many points to score a 5, etc.
The raw score stuff is confusing too, but you can check out Barron’s AP Stat book, they have info like that.</p>
<p>
</p>
<p>t-scores require degrees of freedom; z-scores require variance. Z-scores > t-scores. Since you can calculate variance, it’s better to use the z score.</p>
<p>What are degrees of freedom? How do you calculate degrees of freedom?</p>
<p>It’s the number of factors that can change. df = n - 1</p>
<p>When would we use pdf’s? And would we even need to use them? I’ve only ever used cdf’s myself.</p>
<p>Edit: Pst I’m referring to calculator functions.</p>
<p>In Chi-squared tests, df=(# of rows - 1) (# of columns - 1)</p>
<p>Question:</p>
<p>Sophomore, junior, and senior students at a high school will be surveyed regarding a potential increase in the extracurricular student activities fee. There are three possible responses to the survey question — agree with the increase, do not agree with the increase, or no opinion. A chi-square test will be conducted to determine whether the response to this question is independent of the class inwhich the student is a member. How many degrees of freedom should the chi-square test have? Explain.</p>
<p>According to what i learned i think it is 2. I have a bad teacher.</p>
<p>df for chi-squared = (r-1)(c-1)</p>
<p>r = # of rows
c = # of columns</p>
<p>Since we are comparing 3 groups (Sophs, juniors, seniors) on 3 choices (Yes, no, no opinon),</p>
<p>df = (3-1)(3-1) = 4</p>
<p>if it helps, set up an actual table to visualize it.</p>
<p>It is 4, it came back.</p>
<p>Probability question:</p>
<p>The probability of obtaining a head when a certain coin is flipped is about 0.65. What is the probability that heads would be obtained 15 or fewer times when this coin is flipped 25 times? Explain. (round your answer to two decimal places)</p>
<p>binomcdf(25,.65,15) = 0.3697</p>
<p>Whats binomcdf? What’s it used for?</p>
<p>Well, ur question states what is the probability that heads would be obtained 15 or fewer times.</p>
<p>binomcdf is a function on the 83/84. It basically is the cumulative of the probability that heads would show up 1 time in 25 flips + 2 in 25 + 3 in 25 … + 15 in 25</p>
<ul>
<li>used for binomial distributions</li>
<li>you use “cdf” when you want a range of things, as opposed to “pdf” where you just want one probability</li>
<li>binomcdf(n, p, X), where X = the number of times that you want. If you use cdf, X = the number of times OR LESS</li>
</ul>
<p>did that make sense?</p>
<p>So much tension/worry in this thread. I should be studying for it, but the game is on! (Rockets vs. Lakers)</p>
<p>The probability of the Houston Rockets winning is .001. SIGH :(</p>