| Hand in Wednesday . I think
they're all do-able. Using SPSS for one-sample procedures (with front page of Handout) Dataset as SPSS file, Dataset as text (.dat) file (If you import from the text file, remember to check that the Measure is Scale) A. Redo the example on the handout, getting the result of example 18.3 p. 453, 18.27 Sharks (Use SPSS) Use SPSS to find the confidence interval, also to do the test, for the practice. p. 457, 18.41 Auto crankshafts (Use SPSS) = = = = = = = = = = = = = = = = = = = = = = Matched pairs, and robustness (by hand unless it says SPSS) p. 455, 18.37 measuring placebo effect Use Table C. You can check with the Excel t-procedures p. 446, 18.11and 12 newts healing. Find the differences by hand, and make a stemplot by hand. Use SPSS (back page of Handout) to do the test and CI. You can use the "Paired Sample" method." p. 448, 18.13 newts with outlier You may find the differences by hand, and do the stemplot by hand, or use SPSS. Use SPSS to do the tests. To eliminate the outlier, you can just delete that row from the data set. p. 450, 18.14 Reading scores Use Table C. Also, what IS the standard deviation? You can check with the Excel t-procedures , plug in the sample size and what you think is the s.d. and see if you get the given SE . Also , you may find that the mean is (statistically) significantly below the basic level. Is the difference large enough to be important? (I don't know...) p. 455, 18.36b calcium/blood pressure conditions p. 454, 18.34 growing trees faster. Use SPSS. + + + + + + + + + + + Chapter 19 problems, with echos of Chapters 8 and 9. Note that we can use the same analysis method whether data is from a sample (Example 19.1b) or an experiment (Example 19.1 a, c) or an observational study. p. 461, 19.1, 2, 3, 4. For each, after deciding which design it is, tell if the data comes from a sample, an observational study, or an experiment. |
Read, to discuss |
Optional & & & Leftover problems from Day 30 & & & & & & & & See notes Day 39 These ideas are related to those in Ch. 15. You can get the answers visually by using the Statistical Significance Applet p. 290, 11.39 Pollutants in auto exhausts For 11.39: You might want to know L so that if you tested your 25 cars and found a high value of x-bar, you would be able to compare it with L; if it was greater than L, you would go back to the manufacturer and say "I believe you sold me a batch of bad cars, because the chances of getting an average emission level this high if the exhaust system is working properly is only 1 in 100. It is more reasonable to believe the exhaust system is not working, than that we "are" that 1 in 100 possibility." p. 290, 11.38 Glucose testing If we use this cutoff level L to say that people (with a mean of 4 tests) over L "have diabetes", then the chances of declaring that someone "has diabetes" when they really are OK (with mean 125mg/dl) is .05. .05 or 5% is the chance of a "false positive" using this protocol, when the real mean is 125. & & & & & & & & & & & & & & & & & & |
Jenn's review times: She has emailed everyone with a list of your missing HW's. Better late than never!
Tuesday 5th 3:30-5:30pm
Wednesday 6th 6:30-8pm
Thursday 7th 6:30-8pm
Sunday 10th 7-8:30pm
Monday 11th 11-noon
I'll be on campus Friday morning (exact times soon), and Tuesday 12th from 12:30 on.
Ch. 18: Inference for population mean
(realistic)
What is the
significance
to Statistics of the Guinness Stout Bottle ?
Homework
questions? Day 40
Get Handout
for SPSS Ch. 18
See Day 40 for notes .
Computer crash prevented showing this,
SPSS work. READ webpage Day 40 and below, BPS4e about Matched pairs (p 444-7)and Robustness
(p.447-9), Ch. 19 pp. 460-61 only.
Another situation which uses
t-statistics is the one in
Chapter 19
"Two-sample problems".
Two random samples, independent of each
other,
from distinct populations. (Populations are normally
distributed)
Often--comparing means from an experiment with two treatments (usually
control and "treatment").
/--- Group 1, n1---- Treatment 1---\
/
\
Random
asst.(?)
Compare results --"means"
\
/
\--- Group 2, n2---- Treatment 2---/
To examine the difference of the two means, µ1
- µ2, we look at the difference of the xbars.
We need the Standard Error of the difference xbar1
- xbar2
,
and then we can proceed as before, more or less (with some
adjustments.)
But we've run out of time....
| Sievers home | Math151-Fall06/Daym41.htm | 11am | 12/4/06 |
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TH 9:40 am | MWF
8:10 am TH 8:15 am MWF 8:30 am W 8:30 am F 8:30 am F 1:30 pm |
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MWF 9:30 am |
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Courses for which meeting times are not listed above; make-up exams |