<p>I took AP Stats first semester…haha, I’m going to fail this exam.</p>
<p>In the calculus exam fr section, it said something like ‘‘don’t write the calculator functions (such as Intetc…)’’</p>
<p>is it also like that for this exam?</p>
<p>if so, how would you write normalcdf(etc…)?</p>
<p>@vargas
P(Z>…)
So normalcdf(1.96,1000) would be written as P(Z>1.96).</p>
<p>Could someone explain to me what 95% confidence means? I always screw this up. Is it something like 95% of all samples taken will contain the true population mean? Or is it 95% of all samples will be within the range?</p>
<p>Paid $87 for this ********</p>
<p>i am ___% confident that the true (proportion, mean, slope) of (the population) is between (lower bound of interval) and (higher bound of interval). </p>
<p>this is pretty much it</p>
<p>t is believed that using a new fertilizer will result in a yield of 1.6 tons per acre. A botanist carries out a two-tailed test on a field of 64 acres. Determine the P-value if the mean yield per acre in the sample is 1.72 tons and the population standard deviation is 0.4. What is the conclusion at a level of significance of 10%? 5%? 1%?</p>
<p>i hate significance testing so much!</p>
<p>@Battlebrick. Ok, so if you are using 95% confidence interval, you could say that 95/100 samples would contain the true population mean? That makes sense, thanks.</p>
<p>
No, you cannot do that.
The only other thing that you can really say is that if you repeated this procedure multiple times, 95% of the confidence intervals calculated would contain the true mean.</p>
<p>95% of the 95% confidence intervals, right?</p>
<p>
Correct.</p>
<p>By the way, in case you guys didn’t know (I just saw this while reading Barron’s, verified online just to make sure)… Chi square tests are only for counts/tallies.</p>
<p>semaphore12, what do you mean? “counts/tallies”?</p>
<p>@Vargas </p>
<p>If my calculations are correct:</p>
<p>Step 1: u=1.6 acres<br>
u is not equal to 1.6 acres
Step 2: State conditions : Independence, etc
Step 3: 1 sample Z Test (since population standard deviation is known)
p value = .0164
Step 4: We have evidence to reject the null hypothesis at the 10% and 5% level to conclude the true mean is not equal to 1.6 acres. But at the 1% level we do not have evidence to reject the null hypothesis.</p>
<p>When they ask for different confidence intervals (ie. 95%, 10%, 5%) that would just change the p- value, right?</p>
<p>Good luck to all!</p>
<p>Less than 4 hrs until AP Stat… GOOD LUCK EVERYONE!!!</p>
<p>Hey guys, I don’t really understand the whole ‘find the probability of a Type II error/ Beta’ thing, if any of you can explain to me or send me a link that helps it would be awesome. Thanks!
PS: good luck to the test 3 hours later :D</p>
<p>Everyone REMEMBER: The p-value is the probability of getting a sample statistic similar to (or greater than) the one obtained assuming the null hypothesis is correct!</p>
<p>When do you use pooling for a two proportion test?</p>
<p>@zachb757： I don’t think you do on this test…</p>