| |
Applied Statistical Methods 1000
Assignments
Rules
- All assignments should be your individual work; otherwise, points
will be deducted. [Students who wish to work together on homework
must request my permission to do so in advance.]
- Because answer keys are made available after homework is turned
in, late homeworks will not be accepted. In a valid emergency,
your recitation instructor may make an exception.
- Your homework should be neat and well-organized. Show your work
and circle your answers. Your recitation instructor is a student
like you and will not take time to decipher poor handwriting, put
pages in order, or read notes scrawled in margins.
- Be sure to write or print your name at the top of the first page
of your homework. Put your name or initials at the top of each
additional sheet of paper or computer output. Staple your pages
together.
- Answer keys are placed on file in the Math-Stat Library
(4th floor Thackeray)
on Mondays after assignments are handed in. They are
on two-hour reserve so that you can take them out to be copied.
- Computer output must be circled/underlined and explained in order to receive full credit. Hand in printout of session window and/or graphs, not the worksheet of data values.
- With an Exercise for which you must find an article or internet report,
a copy must be handed in with your work.
Homework 0
Due in lecture January 12. Points shown total 2.
Exercise: Hand in an article or report about a statistical study;
tell what variable or variables are involved and whether they are quantitative
or categorical. If there are two variables, tell which is explanatory and
which is response.
Homework 1
Due in lecture January 19. Points shown total 26.5.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1 pt.] |
1.7(a)(b) |
(page 9) |
|
[1 pt.] |
1.7(a)(b) |
(page 9) |
| [1 pt.] |
1.10 |
(page 9) |
|
[1 pt.] |
1.10 |
(page 9) |
| [1.5 pts.] |
1.12 |
(page 9) |
|
[1.5 pts.] |
1.12 |
(page 10) |
| [1.5 pts.] |
1.17 |
(page 10) |
|
[1.5 pts.] |
1.17 |
(page 10) |
| [.5 pt.] |
1.18(a) |
(page 10) |
|
[.5 pt.] |
1.18(a) |
(page 10) |
| [1.5 pts.] |
2.5(b)(c)(d) |
(page 48) |
|
[1.5 pts.] |
2.15(b)(c)(d) |
(page 59) |
| [2 pts.] |
2.3 |
(page 48) |
|
[2 pts.] |
2.13 |
(page 59) |
| [2.5 pts.] |
2.16 |
(page 49) |
|
[2.5 pts.] |
2.24 |
(page 60) |
| [1 pt.] |
2.26 |
(page 51) |
|
[1 pt.] |
2.40 |
(page 62) |
| [2.5 pts.] |
2.41 |
(page 52) |
|
[2.5 pts.] |
2.54 |
(page 63) |
| [.5 pt.] |
2.54(c) |
(page 53) |
|
[.5 pt.] |
2.76(c) |
(page 64) |
| [1.5 pts.] |
2.56(b)(c)(d) |
(page 53) |
|
[1.5 pts.] |
2.78(b)(c)(d) |
(page 65) |
| [1 pt.] |
2.57(b)(c) |
(page 53) |
|
[1 pt.] |
2.79(b)(c) |
(page 65) |
| [.5 pt.] |
2.84(b) |
(page 55) |
|
[.5 pt.] |
2.117(b) |
(page 68) |
| [2 pts.] |
Exercise |
Pick a quantitative variable from those in the survey.
Use MINITAB to display the variable's values with all three graphs discussed:
a dotplot, a histogram, and a stemplot. Report the median for center,
range for spread, and describe the shape. Be sure to mention if there
are outliers.
|
| [2 pts.] |
Exercise |
Consider the values of one quantitative variable
in our survey compared for two categorical groups. First, state your
expectations about how the quantitative values would compare for the two
groups. Then use MINITAB to get
side-by-side boxplots and report the Five Number Summary for each. Tell
how their centers, spreads, and shapes compare. Use the 1.5*IQR Rule to
report the boundaries for low and high outliers in both groups, and tell
whether there are any outliers according to the Rule.
|
| [2 pts.] |
Exercise |
Find an article or report about an experiment. Tell
what the variables of interest are, whether they are quantitative or
categorical, and which is explanatory and response. Describe the subjects,
treatments, whether or not the study was blind, etc.
|
| [2 pts.] |
Exercise |
Find an article or report about an observational study.
Tell what the variables of interest are, whether they are quantitative or
categorical, which is explanatory and response (if there are two variables).
Are there any potential confounding variables that should have been controlled
for? Are there any other pitfalls of concern?
|
Homework 2
Due in lecture January 26. Points shown total 17.5.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [.5 pts.] |
3.9 |
(page 82) |
|
[.5 pts.] |
4.9 |
(page 143) |
| [.5 pts.] |
3.10(refer to 3.9(b) |
(page 82) |
|
[.5 pts.] |
4.10(refer to 4.9(b) |
(page 143) |
| [.5 pts.] |
3.11(refer to 3.9(b) |
(page 82) |
|
[.5 pts.] |
4.11(refer to 4.9(b) |
(page 143) |
| [.5 pt.] |
3.27(b) |
(page 83) |
|
[.5 pt.] |
4.29(b) |
(page 144) |
| [.5 pt.] |
3.39 |
(page 84) |
|
[.5 pt.] |
4.47 |
(page 146) |
| [.5 pt.] |
3.40 |
(page 84) |
|
[.5 pt.] |
4.48 |
(page 146) |
| [1 pt.] |
3.54 |
(page 85) |
|
[1 pt.] |
4.62 |
(page 147) |
| [.5 pt.] |
3.59 |
(page 86) |
|
[.5 pt.] |
4.66 |
(page 147) |
| [1 pt.] |
3.62 |
(page 86) |
|
[1 pt.] |
4.69 |
(page 147) |
| [1 pt.] |
4.4 |
(page 121) |
|
[1 pt.] |
3.20 |
(page 108) |
| [1.5 pts.] |
4.7 |
(page 121) |
|
[1.5 pts.] |
3.10 |
(page 107) |
| [.5 pt.] |
4.10 |
(page 122) |
|
[.5 pt.] |
3.25 |
(page 108) |
| [.5 pt.] |
4.20 |
(page 123) |
|
[.5 pt.] |
4.22 |
(page 144) |
| [1 pt.] |
4.31 |
(page 124) |
|
[1 pt.] |
3.41 |
(page 110) |
| [1 pt.] |
4.38 |
(page 124) |
|
[1 pt.] |
3.47 |
(page 110) |
| [1 pt.] |
4.57(a)(d) |
(page 125) |
|
[1 pt.] |
3.67(a)(d) |
(page 112) |
| [1.5 pts.] |
4.81 |
(page 128) |
|
[1.5 pts.] |
3.100 |
(page 115) |
| [2 pts.] |
Exercise |
Find an article or internet report about a sample
survey. Tell if the variable(s) of interest is quantitative or categorical.
Then tell how the individuals were selected and whether or not you believe
they adequately represent the population of interest. Discuss whether any
of the 5 common problems in the selection process (using the wrong sampling
frame, etc.) apply, or if any
of the 7 pitfalls in the surveying process (deliberate bias, etc.)
apply. Were the questions open or closed?
|
| [2 pts.] |
Exercise |
Pick two quantitative variables from our survey,
decide on roles of explanatory and response, and tell what you expect
to see in terms of their relationship. Use MINITAB to explore
the relationship between them: start by assessing the scatterplot.
Be sure to mention direction, form, strength, and outliers. Your
summary should tell the value of the correlation r and the equation
of the regression line, if the form appeared linear. Summarize your
findings in the contextof the specific variables chosen.
|
Homework 3
Due in lecture February 2. Points shown total 22.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1 pt.] |
5.1(c)(d) |
(page 161) |
|
[1 pt.] |
5.1(c)(d) |
(page 181) |
| [1.5 pts.] |
5.3(b)(c)(d) |
(page 161) |
|
[1.5 pts.] |
5.3(b)(c)(d) |
(page 182) |
| [1 pt.] |
5.4 |
(page 162) |
|
[1 pt.] |
5.4 |
(page 182) |
| [1 pt.] |
5.10 |
(page 163) |
|
[1 pt.] |
5.10 |
(page 183) |
| [.5 pt.] |
5.23 |
(page 164) |
|
[.5 pt.] |
5.25 |
(page 185) |
| [.5 pt.] |
5.32 |
(page 165) |
|
[.5 pt.] |
5.38 |
(page 185) |
| [6 pts.] |
5.55 |
(page 167) |
|
[6 pts.] |
5.73 |
(page 189) |
| Use MINITAB; mark and hand in relevant output along with specific
answers to textbook questions. |
| [1 pt.] |
6.3(d)(e) |
(page 193) |
|
[1 pt.] |
6.5(d)(e) |
(page 218) |
| [2.5 pts.] |
6.7 |
(page 194) |
|
[2.5 pts.] |
6.10 |
(page 218) |
| [.5 pt.] |
6.15 |
(page 194) |
|
[.5 pt.] |
6.17 |
(page 219) |
| [1.5 pts.] |
6.25 |
(page 195) |
|
[1.5 pts.] |
6.30 |
(page 220) |
| [1 pt.] |
6.50 |
(page 199) |
|
[1 pt.] |
6.58 |
(page 224) |
| [2 pts.] |
Exercise |
Read Boys spur marriage and complete a two-way
table for this study consistent with all the numbers reported. Assume
that the 600 children are equally divided between boys and girls, and
assume that half of the fathers of girls ended up marrying the mother.
If the proportion marrying the mother is 42% higher in the case of boys,
how many would that be?
Use a chi-square procedure to tell whether the difference observed is
statistically significant.
|
| [2 pts.] |
Exercise |
Pick two categorical variables from our survey, decide
which should be explanatory and response, and discuss if and how you expect
them to be related. Then analyze the relationship
between them: compare conditional percentages in the response category of
interest and tell whether the observed difference seems to you to be
significant. Then compute a table of counts expected if the variables were
not related, and compute the chi-square statistic. Use Table A.5 to tell
whether there is a statistically significant relationship.
|
Homework 4
Due in lecture February 9. Points shown total 13.5.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1.5 pts.] |
7.17 |
(page 241) |
|
[1.5 pts.] |
7.26 |
(page 271) |
| [1 pt.] |
7.18 |
(page 241) |
|
[1 pt.] |
7.17 |
(page 270) |
| [1 pt.] |
7.25(c)(d) |
(page 242) |
|
[1 pt.] |
7.24(c)(d) |
(page 271) |
| [2 pts.] |
7.34 |
(page 242) |
|
[2 pts.] |
7.34 |
(page 271) |
| [1.5 pts.] |
7.78 |
(page 246) |
|
[1.5 pts.] |
7.78 |
(page 275) |
| [1 pt.] |
7.83 |
(page 246) |
|
[1 pt.] |
7.83 |
(page 276) |
| [.5 pt.] |
7.85 |
(page 246) |
|
[.5 pt.] |
7.85 |
(page 276) |
| [.5 pt.] |
7.93 |
(page 247) |
|
[.5 pt.] |
7.93 |
(page 277) |
| [.5 pt.] |
7.94 |
(page 247) |
|
[.5 pt.] |
7.94 |
(page 277) |
| [2 pts.] |
Exercise |
Write up and email me (directly, not as an attachment) a
personal coincidence
story that happened to you. Were the occurrences really so unlikely?
[Note: these will be posted with your initials on the course website
unless you request otherwise.]
|
| [2 pts.] |
Exercise |
Use the class survey to report the probability
distribution of year for the surveyed undergraduates (years 1, 2, 3, and
4). [You will need to tally the years and adjust the total to exclude
"other" students.] Find the mean, variance, and standard deviation. Use mean and
standard deviation in a sentence about the distribution of year in order
to tell what is typical for surveyed students.
|
Homework 5
Due in lecture February 23. Points shown total 17.5.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1 pt.] |
8.6 |
(page 285) |
|
[1 pt.] |
8.9 |
(page 322) |
| [1 pt.] |
8.7(b)(c) |
(page 285) |
|
[1 pt.] |
8.10(b)(c) |
(page 322) |
| [1.5 pts.] |
8.18 |
(page 286) |
|
[1.5 pts.] |
8.21 |
(page 323) |
| [.5 pt.] |
8.27 |
(page 287) |
|
[.5 pt.] |
8.30 |
(page 323) |
| [1 pt.] |
8.34(a)(b) |
(page 287) |
|
[1 pt.] |
8.37(a)(b) |
(page 324) |
| [1.5 pts.] |
8.43(a)(c)(d) |
(page 288) |
|
[1.5 pts.] |
8.49(a)(c)(d) |
(page 325) |
| [1 pt.] |
8.44(f)(g) |
(page 288) |
|
[1 pt.] |
8.50(f)(g) |
(page 325) |
| [1.5 pts.] |
8.45 |
(page 288) |
|
[1.5 pts.] |
8.51 |
(page 325) |
| [1.5 pts.] |
8.49(b)(c)(d) |
(page 288) |
|
[1.5 pts.] |
8.53(b)(c)(d) |
(page 325) |
| [1.5 pts.] |
8.50 |
(page 288) |
|
[1.5 pts.] |
8.54 |
(page 325) |
| [1 pt.] |
8.51(b)(c) |
(page 288) |
|
[1 pt.] |
8.57(b)(c) |
(page 325) |
| [1 pt.] |
8.53(c)(d) |
(page 289) |
|
[1 pt.] |
8.58(c)(d) |
(page 325) |
| [1 pt.] |
8.54(d)(e) |
(page 289) |
|
[1 pt.] |
8.59(d)(e) |
(page 325) |
| [.5 pt.] |
8.56 |
(page 289) |
|
[.5 pt.] |
8.61 |
(page 326) |
| [1 pt.] |
8.60(a)(b) |
(page 289) |
|
[1 pt.] |
8.65(a)(b) |
(page 326) |
| [1 pt.] |
8.62 |
(page 289) |
|
[1 pt.] |
8.67 |
(page 326) |
Homework 6
Due in lecture March 2. Points shown total 17.5.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [.5 pts.] |
9.6(a) |
(page 319) |
|
[.5 pts.] |
9.6(a) |
(page 384) |
| [1 pt.] |
9.12(c)(d) |
(page 319) |
|
[1 pt.] |
9.31(c)(d) |
(page 386) |
| [.5 pt.] |
9.13 |
(page 319) |
|
[.5 pt.] |
9.32 |
(page 386) |
| [1 pt.] |
9.17(b)(c) |
(page 320) |
|
[1 pt.] |
9.36(b)(c) |
(page 387) |
| [1 pt.] |
9.28(b)(d) |
(page 321) |
|
[1 pt.] |
9.57(b)(d) |
(page 389) |
| [.5 pt.] |
9.30 |
(page 321) |
|
[.5 pt.] |
9.59 |
(page 390) |
| [1 pt.] |
9.45(c)(d) |
(page 322) |
|
[1 pt.] |
9.85(c)(d) |
(page 393) |
| [1 pt.] |
9.47(c)(d) |
(page 323) |
|
[1 pt.] |
9.89(c)(d) |
(page 393) |
| [1.5 pts.] |
9.55(b)(c)(d) |
(page 323) |
|
[1.5 pts.] |
9.92(b)(c)(d) |
(page 393) |
| [.5 pt.] |
9.56 |
(page 323) |
|
[.5 pt.] |
9.93 |
(page 393) |
| [1.5 pts.] |
9.69 |
(page 324) |
|
[1.5 pts.] |
9.126 |
(page 396) |
| [1.5 pts.] |
9.70 |
(page 324) |
|
[1.5 pts.] |
9.127 |
(page 397) |
| [2 pts.] |
Exercise |
Assume the proportion of females in all intro Stat classes
is p=.5.
What are the mean and standard deviation of sample
proportion, if population proportion were indeed .5?
Use our class survey responses to find the sample proportion of
females in the survey.
Then use a normal approximation to find the
probability of a sample proportion as high as the one observed, if the
population proportion
were truly .5. Characterize the results, based on your probability, in words
such as ``not unusual'', ``unlikely'', ``almost impossible'', etc. Finally,
tell whether you believe p is .5.
|
| [2 pts.] |
Exercise |
If students each picked a number truly at random from 1
to 20, then their responses would follow a ``uniform distribution'', with
each of the numbers appearing with probability 1/20=.05. It can
be shown that the
mean of all the numbers between 1 and 20 is 10.5, and the standard deviation
is 5.77. What are the mean and standard deviation of sample
mean selection for a sample of 400? students, if their selections are truly
random?
Use our class survey responses to find the sample mean ``random'' number
selected. Then use a normal approximation to find the
probability of a sample mean as high as the one observed, if the
population mean
were truly 10.5. Characterize the results, based on your probability, in words
such as ``not unusual'', ``unlikely'', ``almost impossible'', etc. Finally,
tell whether you have statistical evidence of bias in favor of higher numbers.
|
| [2 pts.] |
Exercise |
Find an article or report that includes mention of
sample size and summarizes values of a categorical variable with a count,
proportion, or percentage. Based on that information, set up a 95%
confidence interval for population proportion in the category of interest.
|
Homework 7
Due in lecture March 16. Points shown total 10.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1 pt.] |
10.1(a)(b) |
(page 349) |
|
[1 pt.] |
10.1(a)(b) |
(page 433) |
| [2 pts.] |
10.11(a)(b)(c)(d) |
(page 350) |
|
[2 pts.] |
10.35(a)(b)(c)(d) |
(page 436) |
| [1.5 pts.] |
10.13 |
(page 350) |
|
[1.5 pts.] |
10.21 |
(page 435) |
| [.5 pt.] |
10.14 |
(page 350) |
|
[.5 pt.] |
10.36 |
(page 436) |
| [.5 pt.] |
10.19(a) |
(page 350) |
|
[.5 pt.] |
10.13(a) |
(page 434) |
| [.5 pt.] |
10.24 |
(page 351) |
|
[.5 pt.] |
10.27 |
(page 435) |
| [1 pt.] |
10.28 |
(page 351) |
|
[1 pt.] |
10.51 |
(page 438) |
| [.5 pt.] |
10.31 |
(page 351) |
|
[.5 pt.] |
10.53(a) |
(page 438) |
| [.5 pt.] |
10.42 |
(page 352) |
|
[.5 pt.] |
10.62 |
(page 439) |
| [2 pts.] |
Exercise |
Here is an excerpt from a Pittsburgh Post-Gazette article entitled
Criminal pasts cited for many city school bus drivers:
"State auditors checking the records of a random sample of 100 city bus drivers
have found that more than a quarter of them had criminal histories.
The audit also found that 26 of the drivers were never checked for child abuse
histories---in Pennsylvania schools, a mandate for all employees and even some
volunteers.
In all, the auditors discovered 80 convictions for various offenses among the
100 sampled. Thirty-four of those incidents occurred more than ten years ago,
including one rape and four drug offenses.
In Pennsylvania, it's perfectly legal for school officials to hire a bus driver
with certain convictions that are more than five years old---but that doesn't
mean they should, state Auditor General Robert P. Casey Jr. said yesterday
in releasing the report.
``No one convicted of rape should be driving a school bus full of children,''
said Casey, who also said he was disappointed with the school district's
initial response to the audit. ``The General Assembly needs to look at this
law,'' he said.
A series of problems last year with school bus drivers---including a February
accident that was nearly fatal to an 8-year-old Elliott girl---prompted Casey
to take a closer look at Pittsburgh's staff of 750 drivers, he said.
When his office presented their results to school officials about eight months
ago, Casey said, 'they were very reluctant to do anything about it,' and sent
him only a brief response outlining what steps were being taken to remedy the
problems..."
Note that the article states that about 25% in a sample of Pittsburgh school
bus drivers had criminal records. Report a 98% confidence interval for the
proportion of all Pittsburgh school bus drivers with criminal records. One
of the conditions for our approximation is not quite met; what is it?
|
Homework 8
Due in lecture March 23. Points shown total 25.Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1 pt.] |
11.1(c)(d) |
(page 382) |
|
[1 pt.] |
12.8(c)(d) |
(page 539) |
| [.5 pt.] |
11.6 |
(page 383) |
|
[.5 pt.] |
12.13 |
(page 539) |
| [1 pt.] |
11.10(a)(b) |
(page 383) |
|
[1 pt.] |
12.19(a)(b) |
(page 540) |
| [1.5 pts.] |
11.19(a)(b)(c) |
(page 384) |
|
[1.5 pts.] |
12.28(a)(b)(c) |
(page 540) |
| [3 pts.] |
11.27 |
(page 384) |
|
[3 pts.] |
12.48 |
(page 542) |
| [.5 pt.] |
11.29 |
(page 385) |
|
[.5 pt.] |
12.50 |
(page 543) |
| [.5 pt.] |
11.36 |
(page 385) |
|
[.5 pt.] |
12.73 |
(page 545) |
| [.5 pt.] |
11.45 |
(page 386) |
|
[.5 pt.] |
12.30 |
(page 541) |
| [2 pts.] |
11.55 |
(page 387) |
|
[2 pts.] |
12.83 |
(page 546) |
| [1 pt.] |
12.2(b)(c) |
(page 425) |
|
[1 pt.] |
11.3(b)(c) |
(page 484) |
| [1 pt.] |
12.10(a)(b) |
(page 426) |
|
[1 pt.] |
11.8(b)(c) |
(page 485) |
| [1 pt.] |
12.13(b)(c) |
(page 426) |
|
[1 pt.] |
11.11(b)(c) |
(page 485) |
| [.5 pts.] |
12.26(e) |
(page 427) |
|
[.5 pts.] |
11.23(e) |
(page 486) |
| [1.5 pts.] |
12.28(a)(b)(c) |
(page 427) |
|
[1.5 pts.] |
11.25(a)(b)(c) |
(page 486) |
| [1 pt.] |
12.32 |
(page 428) |
|
[1 pt.] |
11.29 |
(page 487) |
| [.5 pt.] |
12.36(c) |
(page 428) |
|
[.5 pt.] |
11.42(c) |
(page 488) |
| [3.5 pts.] |
12.42 |
(page 429) |
|
[3.5 pts.] |
11.51 |
(page 489) |
| Use MINITAB; mark and hand in relevant output along with specific
answers to textbook questions. |
| [.5 pt.] |
12.69(c) |
(page 432) |
|
[.5 pt.] |
11.73(c) |
(page 492) |
| [2 pts.] |
Exercise |
In a previous Exercise, we explored the sampling
distribution
of sample proportion of females, when random samples are taken from a
population where the proportion of females is .5. We noted the sample
proportion of females among surveyed Stats students, and calculated by hand
the probability of observing such a high sample proportion, if population
proportion were really only .5. We used this probability to decide whether
we were willing to believe that population proportion is in fact .5.
For this Exercise, address the same question by carrying out a formal
hypothesis test using MINITAB. Be sure to specify the appropriate
alternative hypothesis. State your conclusions clearly in context.
|
| [2 pts.] |
Exercise |
Refer to the article How not to catch a spy:
Use a lie detector, which reports at the bottom of the first column,
``Even if the test were designed to catch eight of every 10 spies, it would
produce false results for large numbers of people. For every 10,000 employees
screened, Fienberg said, eight real spies would be singled out, but 1,598
innocent people would be singled out with them, with no hint of who's a spy
and who isn't.'' Based on this information, set up a two-way table,
classifying 10,000 employees as actually being spies or not, and being singled
out as a spy by the lie detector or not.
Report the probability of a Type I Error and of a Type II Error.
If someone is identified by the lie detector as being a spy, what is the
probability that he or she is actually a spy?
|
Homework 9
Due in lecture March 30. Points shown total 25.5.Complete them in order shown.
| [2 pts.] |
Exercise |
In a previous Exercise, we explored the sampling
distribution
of sample mean number selected, when random samples are taken from a
population where all numbers between 1 and 20 are equally likely, so
population mean is 10.5. We noted the sample mean selection by surveyed Stats
students, and calculated by hand
the probability of observing such a high sample mean, if population
mean were really only 10.5. We used this probability to decide whether
we were willing to believe that population mean was in fact 10.5, or if
students were rather biased towards higher numbers.
For this Exercise, address the same question by using MINITAB to set up a
confidence interval for unknown population mean selection, given that
population standard deviation is 5.77. Does your interval contain 10.5?
What do you conclude?
|
| [2 pts.] |
Exercise |
For this Exercise, address the same question again by using MINITAB to set up a
confidence interval for unknown population mean selection, but this time
assume population standard deviation is unknown. Does your interval contain
10.5? What do you conclude?
|
| [2 pts.] |
Exercise |
Find paired data in our survey, such as math and verbal
SATs, ages of mothers and fathers, heights of females and their mothers,
or heights of males and their fathers. Use MINITAB to test Ho: mu(d)=0
against an appropriate Ha. State your conclusion in terms of the
variable chosen.
|
| [2 pts.] |
Exercise |
Compare values of a quantitative survey variable for
two categorical groups, such as males and females or on and off campus
students, by testing Ho: mu1-mu2=0 against an appropriate Ha.
State your conclusion in terms of the variable chosen.
|
| [2 pts.] |
Exercise |
Read the article The most important meal, which
reports that in a study of American eight-graders in 96 public schools in
San Diego, New Orleans, Minneapolis, and Austin, overweight students were
more likely to skip breakfast than students who were not overweight.
Unstack the data in our class survey according to gender, then for each
gender group test the null hypothesis of equal weights for students who
did and did not eat breakfast, according to their survey responses. Make
sure to formulate the correct alternative hypothesis.
|
| [2 pts.] |
Exercise |
Read Science lifts 'mummy's curse' and use the
means for Age at death, exposed vs. unexposed, along with the sample
sizes n and standard deviations (in parentheses) to test for a significant
difference in age at death between those who were and were not exposed to
the ``mummy's curse''. State your conclusions clearly.
|
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1 pt.] |
13.3(a)(b) |
(page 482) |
|
[1 pt.] |
13.1(a)(b) |
(page 588) |
| [2 pts.] |
13.5 |
(page 482) |
|
[2 pts.] |
13.12 |
(page 589) |
| Instead of n=28 or n=81, use n=65 for (a)(b)(c)(d) |
| [3.5 pts.] |
13.7 |
(page 482) |
|
[3.5 pts.] |
13.14 |
(page 589) |
| [2.5 pts.] |
13.11 |
(page 482) |
|
[2.5 pts.] |
13.26 |
(page 590) |
| [1.5 pts.] |
13.14 |
(page 483) |
|
[1.5 pts.] |
13.33 |
(page 591) |
| [1 pt.] |
13.16(d) and add |
(page 483) |
|
[1 pt.] |
13.35(d) and add |
(page 591) |
| (e) If you were using Table A.2, keeping in mind Ha, the value of t,
and the df, what range would you report for the p-value? |
| [.5 pts.] |
13.33(b) |
(page 485) |
|
[.5 pts.] |
13.44(b) |
(page 593) |
| [1.5 pts.] |
13.70 |
(page 489) |
|
[1.5 pts.] |
13.74 |
(page 596) |
| MINITAB is optional |
Homework 10
Due in lecture MONDAY, April 9. Points shown total 9.5.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1.5 pts.] |
14.2 |
(page 518) |
|
[1.5 pts.] |
14.16 |
(page 627) |
| [1 pt.] |
14.11(b)(c) |
(page 519) |
|
[1 pt.] |
14.36(b)(c) |
(page 630) |
| [1.5 pts.] |
14.13(a)(b)(c) |
(page 519) |
|
[1.5 pts.] |
14.18(a)(b)(c) |
(page 628) |
| [1 pt.] |
14.17(c)(d) |
(page 520) |
|
[1 pt.] |
14.21(c)(d) |
(page 628) |
| [.5 pt.] |
14.33 |
(page 522) |
|
[.5 pt.] |
14.12 |
(page 627) |
| [2 pts.] |
Exercise |
Find two quantitative variables from our survey,
summarize their relationship as in Chapter 5 (see Exercise end of HW2), and
then test Ho: beta1=0.
State your conclusions in terms of the variables of interest.
|
| [2 pts.] |
Exercise |
Compare values of a quantitative survey variable for
more than two categorical groups by carrying out an ANOVA test in MINITAB.
State your conclusions in terms of the particular variables chosen.
|
Homework 11
Due in lecture MONDAY, April 16. Points shown total 19.
Complete them in order shown.
|
2nd ed (cover light blue with mirror)
|
|
3rd ed (cover white with green photo of woman)
|
| [1 pt.] |
15.1(c)(d) |
(page 550) |
|
[1 pt.] |
15.1(c)(d) |
(page 658) |
| [1 pt.] |
15.2(c)(d) |
(page 550) |
|
[1 pt.] |
15.4(c)(d) |
(page 658) |
| Use Table A.5. |
| [1 pt.] |
15.14(a)(b) |
(page 552) |
|
[1 pt.] |
15.13(a)(b) |
(page 660) |
| [2 pts.] |
15.41(a)(b)(d) |
(page 556) |
|
[2 pts.] |
15.45(a)(b)(d) |
(page 665) |
| [1 pt.] |
16.1(b)(c) |
(page 584) |
|
[1 pt.] |
16.1(b)(c) |
(page 693) |
| [1.5 pts.] |
16.3 |
(page 584) |
|
[1.5 pts.] |
16.3 |
(page 694) |
| [1.5 pts.] |
16.6(b)(c)(d) |
(page 585) |
|
[1.5 pts.] |
16.6(b)(c)(d) |
(page 694) |
| Your conclusion should state whether or not population means could
be equal. |
| [2 pts.] |
16.7 |
(page 585) |
|
[2 pts.] |
16.7 |
(page 695) |
| [5 pts.] |
16.9(a)(b) and add |
(page 585) |
|
[5 pts.] |
16.9(a)(b) and add |
(page 695) |
| (c) State Ho and Ha. (d) Use MINITAB to carry out a test, then state
your conclusions. |
| [1 pt.] |
16.11 |
(page 586) |
|
[1 pt.] |
16.11 |
(page 696) |
| [2 pts.] |
Exercise |
Pick two categorical variables from our survey. Decide
which should be explanatory (row variable) and which response. Use MINITAB
to compare conditional percentages in each row [explanatory variable must
be entered before response] and carry out a chi-square test for a
relationship. Use Table A.5 to give a range for the P-value.
|
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