Homework for Introduction to Statistics - Fall
2000
- Choose textbook problems that interest you and do them.
- You may submit up to six (6) even numbered problems per
class period (none may be submitted on lab days).
- The problem numbers that you turn in will be recorded.
- On randomly selected days, a portion of your homework will be graded.
- Your lowest two graded homework scores will be disregarded.
- Your final homework grade will be the product of the
percentage score from the graded homework and the number of
homework problems turned in. The maximum final homework
score will be 150.
- If you would like the challenge of doing harder problems
a bonus of 1.5% will be given for any chapter in which
your median problem number exceeds that of the chapter.
- There are 6 or 7 computer labs to be done on Excel/SPSS.
- Lab reports will only be accepted in electronic form.
- The file name
is to be ZYXLab1 (assuming your name is Zilow Yves Xerlow)
- Lab reports will receive 10 points if they are done at some
reasonable level, 9 if they are up to 2 days late, and 5 if they
are up to a week late or done at less than a reasonable level. Your
lowest lab score will be dropped.
- The maximum final lab score will be 50.
- There will be 6 or 7 commentaries to be done in Word.
- These will only be accepted in electronic form.
- The file name
is to be ZYXCom1 (assuming your name is Zilow Yves Xerlow)
- Commentaries will receive 10 points if they are done at some
reasonably coherent level, 9 if they are up to 2 days late, and 5 if they
are up to a week late or done at less than a coherent level. Your
lowest commentary score will be dropped.
- The maximum final commentary score will be 50.
Suggestions:
6.18
a) Either Consumers in Indiana or U.S. Consumers
b) The first of the three will be 18.67+-1.96*(24.95/sqrt(201))
c) If the confidence intervals in (b) overlap, then there probably is no difference otherwise there is a real difference.
6.22
The margin of error was higher because they asked far fewer men. Sample size determines the size of the margin of error.
6.10
(a) Compute x-bar +- z*(sigma/sqrt(n)) as 10.0023 +- 2.326(0.0002/sqrt(5))
(b) Set m=0.0001, z*=2.326, sigma=0.0002, and solve for n in the margin of error formula.
6.46
The hypothesis of "no difference" tells you that this is a two sided test.
Look up the area to the left of z=-1.37 and then double it to get your P value.
Compare this to the values in (a) and (b).
7.6
(a) df=25-1=24
(b) t=1.059, t=1.318
(c) P=1-0.70=0.30 and P=1-0.80=0.20
(d) You can do this.
7.12
(a) H0:mu=0
Ha:mu>0 (it says "increases")
t=(332-0)/(108/sqrt(200))
(b) 332+-2.626*(108/sqrt(200))
(c) How many cases? See page 380's yellow box
7.32
a) Think about how a subject who knows they are being watched could increase the number of species of trees in logged areas.
b) Put the data into Excel or SPSS and analyze it using a two-sample t-test.
c) Use the output from the software to build a 90% confidence interval.
7.36
a) Plot each by hand on a stem and leaf plot.
b) Put the data into Excel or SPSS and run a two-sample t-test.
c) Use the output from the software to build a 90% confidence interval.
7.42
For the information in Analysis 1, plug these numbers into the statistic on the preceding page. Repeat for Analysis 2. Would you draw the same conclusion in each case?
7.44
This is a good problem to use in test preparation. It covers lots of good ideas.
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Last modified on 12-Aug-2000
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