Key
The 1st Hourly
Math 1107
Summer Term 2009
Protocol
You will use only the
following resources: Your individual calculator; individual tool-sheet (single
8.5 by 11 inch sheet); your writing utensils; blank paper (provided by me) and
this copy of the hourly. Do not share these resources with anyone else.
In each case, show complete
detail and work for full credit. Follow case study solutions and sample hourly
keys in presenting your solutions. Work all six cases. Using only one side of
the blank sheets provided, present your work. Do not write on both sides of the
sheets provided, and present your work only on these sheets. All of your work
goes on one side each of the blank sheets provided. Space out your work. Do not
share information with any other students during this hourly.
Show all work and full detail for full credit. Provide
complete discussion for full credit.
Sign and Acknowledge:
I agree to follow this
protocol.
______________________________________________________________________________________
Name (PRINTED)
Signature Date
Case One |
Random Variables | Color Slot Machine
Probability and Random Variables
Pair of Dice
We have a pair of dice. We
assume that the dice operate separately and independently of each other. The
dice are not fair – here are their probability models:
1st Face |
Pr{1st Face} |
2nd Face |
Pr{2nd Face} |
1 |
2/10 |
2 |
1/15 |
7 |
3/10 |
3 |
2/15 |
8 |
5/10 |
4 |
3/15 |
|
|
5 |
4/15 |
|
|
6 |
5/15 |
Suppose that our experiment
consists of tossing the dice, and noting the resulting face-pair.
List the possible face-pairs, and compute a
probability for each pair.
Denote the face-value pairs as (d5 face
value, d3 face value).
Pair→ Hyp |
2 |
3 |
4 |
5 |
6 |
1 |
(2,1) |
(3,1) |
(4,1) |
(5,1) |
(6,1) |
7 |
(2,7) |
(3,7) |
(4,7) |
(5,7) |
(6,7) |
8 |
(2,8) |
(3,8) |
(4,8) |
(5,8) |
(6,8) |
Then compute the pair probabilities as Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Define HYP = HIGHTIE2 + LOWTIE2.
Compute the values and
probabilities for HYP.
Define HYP as (d5 face value)2 + (d3 face value)2
Pair→ Hyp |
2 |
3 |
4 |
5 |
6 |
1 |
(2,1) →4+1=9 |
(3,1) →9+1=10 |
(4,1) →16+1=17 |
(5,1) →25+1=26 |
(6,1) →36+1=37 |
7 |
(2,7) →4+49=53 |
(3,7) →9+49=58 |
(4,7) →16+49=65 |
(5,7) →25+49=74 |
(6,7) →36+49=85 |
8 |
(2,8) →4+64=68 |
(3,8) →9+64=73 |
(4,8) →16+64=79 |
(5,8) →25+64=89 |
(6,8) →36+64=100 |
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Case Two | Long Run Argument and Perfect Samples | Plurality
in US Resident Pregnancies
Plurality is the number of
siblings born as the result of a single pregnancy. Singleton pregnancies yield
one born infant, twin pregnancies yield two infants and triplet pregnancies
yield three infants. Suppose that the
probabilities tabled below apply to pregnancies to US resident mothers with
pregnancies yielding one or more live births:
Plurality |
Probability |
Singleton (1) |
0.9660 |
Twins (2) |
0.0330 |
Triplets+ (3 or more) |
0.0010 |
Total |
1.00 |
1. Interpret
each probability using the Long Run Argument.
In long runs of random sampling,
approximately 96.6% of live births to US resident mothers were singleton
births.
In long runs of random sampling,
approximately 3.3% of live births to US resident mothers were twin births.
In long runs of random sampling,
approximately 0.1% of live births to US resident mothers were
triplet or higher order multiple births.
2. Compute and
discuss Perfect Samples for n=3000.
The expected counts for n=3000 are
ESingleton =
3000*PSingleton = 3000*.9660 = 2898
ETwin =
3000*PTwin = 3000*.033 = 99
ETriplets+ = 3000*PTriplets+
= 3000*.001 = 3
In random samples of 3,000 live births to US
resident mothers, approximately 2898 sampled live births are singleton live
births.
In random samples of 3,000 live births to US
resident mothers, approximately 99 sampled live births are twinned live births.
In random samples of 3,000 live births to US
resident mothers, approximately 3 sampled live births are triplet or higher
order multiple live births.
Case Three | Color Slot Machine | Conditional
Probabilities
Here is our slot machine – on
each trial, it produces a 8-color sequence, using the
table below:
Sequence* |
Probability |
BBRRYRRR |
.10 |
RGRGBRRB |
.10 |
BBGGYGBR |
.15 |
GRRYBRGG |
.15 |
BGYGYGYY |
.20 |
RRYYGBBY |
.10 |
YYGBYYRR |
.20 |
Total |
1.00 |
*B-Blue, G-Green, R-Red, Y-Yellow, Sequence is numbered
from left to right: (1st 2nd 3rd 4th
5th6th7th 8th )
Compute the following conditional probabilities:
Pr
Blue Shows
Sequence* |
Probability |
BBRRYRRR |
.10 |
RGRGBRRB |
.10 |
BBGGYGBR |
.15 |
GRRYBRGG |
.15 |
BGYGYGYY |
.20 |
RRYYGBBY |
.10 |
YYGBYYRR |
.20 |
Total |
1.00 |
Pr
Pr
.10 + .10 + .15 +
.15 + .20 + .10 + .20 = 1.00
Blue and “Yellow Shows Exactly Three Times”
Sequence* |
Probability |
RRYYGBBY |
.10 |
Pr
Pr
Pr
“BR” Shows
Sequence* |
Probability |
BBRRYRRR |
.10 |
RGRGBRRB |
.10 |
BBGGYGBR |
.15 |
GRRYBRGG |
.15 |
Total |
.50 |
Pr
Pr
.10 + .10 + .15 + .15 = .50
Yellow and “BR” Shows
Sequence* |
Probability |
BBRRYRRR |
.10 |
BBGGYGBR |
.15 |
GRRYBRGG |
.15 |
Total |
.40 |
Pr
Pr
.10 +.15 + .15 = .40
Pr
Pr
Red Shows
Sequence* |
Probability |
BBRRYRRR |
.10 |
RGRGBRRB |
.10 |
BBGGYGBR |
.15 |
GRRYBRGG |
.15 |
RRYYGBBY |
.10 |
YYGBYYRR |
.20 |
Total |
1.00 |
Pr
Pr
.10 + .10 + .15 +
.15 +.10 + .20 = .80
Green and Red Show
Sequence* |
Probability |
RGRGBRRB |
.10 |
BBGGYGBR |
.15 |
GRRYBRGG |
.15 |
RRYYGBBY |
.10 |
YYGBYYRR |
.20 |
Total |
1.00 |
Pr
Pr
.10 + .10 + .15 +
.15 +.10 + .20 = .80
Pr
Case Four | Color Slot Machine | Probability Rules
Using the color slot machine
from case three, compute the
following probabilities. If a rule is specified, you must use that rule.
1. Pr
“RY” Shows
Sequence* |
Probability |
BBRRYRRR |
.10 |
GRRYBRGG |
.15 |
RRYYGBBY |
.10 |
Total |
.35 |
Pr
Pr
.10 + .15 + .10 = .35
2. Pr{ Green Shows 2nd,
3rd or 4th }
Green Shows 2nd, 3rd
or 4th
Sequence* |
Probability |
RGRGBRRB |
.10 |
BBGGYGBR |
.15 |
BGYGYGYY |
.20 |
YYGBYYRR |
.20 |
Total |
.80 |
Pr
Pr
.10 +.15 + .20 + .20
= .65
3. Pr
“GB” Does Not Show
Sequence* |
Probability |
BBRRYRRR |
.10 |
GRRYBRGG |
.15 |
BGYGYGYY |
.20 |
Total |
.45 |
Pr
Pr
.10 +.15 + .20 = .45
Pr
Case Five | Design Fault Spot
In each of the following a brief description of a
design is presented. Briefly identify faults present in the design. Use the
information provided. Be brief and complete.
1. WidgetCorpsä is conducting an Employee Satisfaction Survey. They hire a third party
to conduct the survey, and a random sample of employees is employed in the
survey. The interviews are conducted
after the annual performance and salary reviews, and while the third party
identifies the identities of the respondents on the surveys, it tells the
respondents that these will be removed before the results are given to WidgetCorpsä.
Widget Corps Survey – If the survey is given too close in time to
the annual review, responses may be distorted. Confidentiality is at risk.
2. A sample
survey of US University and College undergraduates is used to study the
sexual habits, knowledge and attitudes of their parents and legal guardians.
Appropriate random sampling of students is used, and there are no problems with
the wording and delivery of the survey instrument.
Parental Sexual Mores Survey – survey the parents directly.
3.
Disease W is a disease caused by an infection. Left untreated, disease W
produces severe and occasionally fatal symptoms and complications. Suppose that
no effective, standard treatments are available. Suppose further that a new
treatment, ugorbitx is available for evaluation. A
clinical trial is proposed to evaluate ugorbitx by
giving all trial subjects ugorbitx. Their results
would be compared to similar groups of untreated patients who are not enrolled
in the trial.
Disease W Clinical Trial – Use a placebo group within the trial
itself.
4.
A clinical trial of a new Hepatitis C (HepC)
treatment is designed as follows: subjects are screened for HepC
infection. Untreated HepC
can lead to liver disease, liver failure, liver cancer and death. Those who
test positive for HepC infection are then told of
their status, and are offered treatment for HepC at
no cost, and are offered enrollment in a comparative clinical trial for the
treatment of HepC infection. Those who qualify and
who give informed consent are then stratified by risk of progression to
symptoms of hepatitis. Those judged to be at high risk are assigned to the new
treatment, those judged to be at moderate risk of progression to symptoms of
hepatitis are assigned to standard treatment, and those judged to be at minimal
risk of progression to symptoms of hepatitis symptoms are assigned to placebo
only.
Hepatitis C Clinical Trial – Use informed consent in the
recruitment of subjects, and randomly assign subject volunteers to treatment.
Case Six | Clinical Trial
Sketch | Non-small Cell Lung Cancer (NSCLC)
A key ability of malignant cells is the ability to
induce angiogensis, the formation of new blood
supply. These cells can release a substance that stimulates the formation of
new blood vessels. This ability is key in the ability
of malignant tumors to survive and grow.
Avastin is a monoclonal antibody that works by attaching to
and inhibiting the action of vascular endothelial growth factor (VEGF) in
laboratory experiments. VEGF is a substance that binds to certain cells to
stimulate new blood vessel formation. When VEGF is bound to Avastin, it cannot stimulate the formation and growth of
new blood vessels.
A number of cancers are driven by the derangement of
cells composing the linings (epidermal cells) of various organs in the body. In
particular, these cells lose control of their growth behaviors, leading to
uncontrolled reproduction of cells. This deranged, accelerated cell reproduction
is key to the ability of malignant tumors to grow.
Tarceva (erlotinib) is an oral
anti-cancer drug under development by OSI Pharmaceuticals, Genentech and Roche.
It is a member of the epidermal growth factor receptor (EGFR) inhibitor class of
agents.
Lung Cancer
Two general types of lung
cancer exist: Non-Small Cell Lung Cancer (NSCLC) and small-cell lung
cancer (SCLC)
The most common type of lung
cancer is NSCLC. Approximately 85% of all lung cancer cases are NSCLC.
Three main types of NSCLC - General treatment options for each of these are the
same:
Squamous cell carcinoma. Most
often related to smoking. These tumors may be found in the mucous membrane that
lines the bronchi. Sometimes the tumor spreads beyond the bronchi. Coughing up blood
may be a sign of squamous cell NSCLC.
Adenocarcinoma (including bronchioloalveolar
carcinoma). Most often found in nonsmokers and women. Cancer is
usually found near the edge of the lung. Adenocarcinoma
can enter the chest lining. When that happens, fluid forms in the chest cavity.
This type of NSCLC spreads (metastasizes) early in the disease to other body
organs.
Large-cell undifferentiated
carcinoma. Rare type of NSCLC. Tumors
grow quickly and spread early in the disease. Tumors are usually larger than
1-1/2 inches.
First-line Treatments for NSCLC:
Surgery:
Removes the tumor. This can be done if the tumor is small and has not spread to
other areas of your body.
Radiation:
Destroys any leftover cancer cells not removed by surgery. This may be done
before surgery to make it easier to remove the tumor. Radiation can also be
done after surgery.
Chemotherapy may help slow the growth of cancer cells and destroy them.
Chemotherapy may be used with radiation to help shrink the tumor before
surgery. It may be used after surgery or radiation to destroy any cancer cells
that may have been left behind.
Consider patients with locally advanced or metastatic
Non-Small Cell Lung Cancer (NSCLC) after failure of at least one previous
chemotherapy regimen.
Consider two treatments: Avastin+Tarceva
and Tarceva.
Sketch a comparative clinical trial for Avastin+Tarceva versus Tarceva
in the treatment of patients with locally advanced or metastatic
Non-Small Cell Lung Cancer (NSCLC) after failure of at least one previous
chemotherapy regimen.
Solution
Purpose
of Treatment: Treatment of patients with locally advanced or metastatic Non-Small Cell
Lung Cancer (NSCLC) after failure of at least one previous chemotherapy
regimen.
We
recruit patients with locally advanced or metastatic Non-Small Cell Lung Cancer (NSCLC)
after failure of at least one previous chemotherapy regimen. Those giving informed consent are then
checked for study eligibity.
We
employ a placebo version of Avastin. Those who are
eligible and who give informed consent are then randomly assigned to either (Avastin and Tarceva) or (PlaceboAvastin
and Tarceva).
Double
blinding is employed – neither the subjects nor the clinical study workers know
the actual individual treatment assignments.
Subjects
are tracked for the following outcomes:
Safety: Side effects, adverse reactions, toxicity,
fatal and severe complications, organ damage or failure, etc…
Effectiveness: Lung cancer status, survival status,
survival time, quality of life.
Work all six (6) cases.