Exams were returned. Comments, and makeup instructions. To redo the Placebo Effect problem, a new problem (posted on the comments page.
Fuzzy Central Limit Theorem, again:
Data whose variation is due to many small independent random
influences will have an approximately normal distribution.
"Quincunx "probability board
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Chapter 6, Introduction to Inference Go
to Day 28
| Continue: Same as given on Day 26 --work on Confidence
Interval stuff, either Activstats or Moore.
the definition of a C.I. p. 302, esp. the "repeated samples" bit, -- or from the webpage, and the formula p.306 for a CI for the mean, including the picture for z* (Fig. 6.6). Be prepared to respond if called on in class to give one of them. Next: relation of margin of error, Confidence level, sample size, (and sigma). Begin Moore 6.2, significance tests. Activstats Ch. 19--Hypothesis tests. It's good, but not in exactly the order we're doing it.Optional, today. Notes for p. 19-1: Act uses "hypothesis test" for what Moore calls "significance test". This is common. activity 1: Try it again. Each time it will reset the bar proportion to a different value. activity 2: Reasoning of hypothesis test. I think it's good, except it uses "unlikely" in the sense of "not very believable" when it's talking about P(Red) = .50. , and we are trying to use "likely" only about random phenomena. It's not a random phenomenon whether P(Red) = .50. In any particular experiment, it either is, or isn't, and if I peek inside the computer program I can tell you which--no probability about it. activity 3: Here the use of "unlikely" is correct--we're taking a sample from the population, so our proportion is a random phenomenon. activity 4: A succinct exposition of the reasoning and terminology. p. 19-2 ACT does only 2-sided tests. But it's good. act 1 is video--therapeutic. touch act 2 is data on above. p=.4something activity 3 gives a chance to organize the info and do it act. 4 introduces alpha level.. act 5 relates C.I. and hypoth test but I think it's confusing: "C.I.contains those values for which we would not reject Ho." Skip it if you like. p. 19-3 Goes through actually doing tests, p-value and alpha. |
| Sec.6.1 , all from Moore
.
p.302, 6.1 poll of women 6.2 95% confidence? 6.3 density of x-bar, and confidence intervals This problem combines the pictures 6.2 and 6.4 For part d, to draw the confidence interval: just choose any point on the horizontal axis of your graph to be x-bar. Measure off the distance m (half the width of the shaded interval) and extend a bar m wide to the left and the right of your point,below the curve. (Like fig. 6.4, the bars with arrows at the ends. The red dots show what the x-bar is for that confidence interval) Choose another point, and repeat.. If your first x-bar was in the shaded interval, pick your second outside the shaded interval, and vice versa. You should note that if x-bar is in the shaded interval, then the confidence interval bar covers mu (280) and if x-bar isn't, then the bar doesn't. -- - - - - - - - - - - - - - - - - - - - - - - - - - Using formula p. 306 for C.I.: 6.6 potassium again. 6.7 comparing CI's for different confidence levels. Also write down the m (margin of error) for each interval. 6.9 comparing CI's for different sample sizes. 6.5 IQ test scores Read pp. 312-13 before doing this one. - - - - - - - - - - - - - - - - - - - - - - - - - - - To be assigned Friday: Cautions; general review and extension p. 314 6.14 internet, response rate p.317, 6.19 newts p. 318, 6.22 men/women CI's p.316, 6.18 consumers/pharmacies |
Read, to discuss
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- - - - - - 6.13, 6.15 (cautions)
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Optional |
| Sievers home | Math151-Sp02/Day29.htm | 3pm | 4/10/02 |