2nd Hourly

Math 1107

Fall Semester 2002

 

Protocol

 

You will use only the following resources:

 

         Your individual calculator;

         Your individual tool-sheet (one (1) 8.5 by 11 inch sheet);

         Your writing utensils;

         Blank Paper (provided by me);

         This copy of the hourly.

 

Do not share these resources with anyone else.

 

Show complete detail and work for full credit.

         Follow case study solutions and sample hourly keys in presenting your solutions.

 

Work all four 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.

 

Do not share information with any other students during this hourly.

 

When you are finished:

 

Prepare a Cover Sheet: Print your name on an otherwise blank sheet of paper. Then stack your stuff as follows:

 

Cover Sheet (Top)

Your Work Sheets

The Test Papers

Your Toolsheet

 

Then hand all of this in to me.

 

Sign and Acknowledge:     I agree to follow this protocol.

 

 

________________________________________________________________________

Name (PRINTED)                     Signature                        Date

 

 

Case One

Descriptive Statistics

Angry Barrels of Monkeys

A company, BarrelCorpÔ manufactures barrels and wishes to ensure the strength and quality of its barrels. Chimpanzees traumatized the company owner as a youth; so the company uses the following test (Angry_Barrel_of_Monkeys_Test) of its barrels:

Ten (10) chimpanzees are loaded into the barrel.  The chimpanzees are exposed to Angry!Monkey!Gas!ä, an agent guaranteed to drive the chimpanzees to a psychotic rage. The angry, raging, psychotic chimpanzees then destroy the barrel from the inside in an angry, raging, psychotic fashion. The survival time, in minutes, of the barrel is noted.

A random sample of 30 BarrelCorpÔ barrels is evaluated using the Angry_Barrel_of_Monkeys_Test, and the survival time in minutes of each barrel is noted. The survival time of each barrel is listed below:

.50, .75, 1, 1,  2,  3, 4,  5, 7, 7, 7.5, 8, 8.3, 8.5, 9, 9.5, 9.75, 10, 12, 12, 14, 23, 25, 27, 28, 28, 29, 29, 30, 31, 31, 32, 32, 34, 34, 35, 36, 37, 38, 39, 40, 41, 42, 51, 53, 54, 56, 57, 58, 62, 65, 70, 75, 77, 80, 85, 90, 240

Compute and interpret the following statistics: sample size, p00, p25, p50, p75, p100, (p100-p75), (p75-p25), (p50-p25). 

Case Two

Summary Intervals

Serum Creatinine and Kidney (Renal) Function

 

Healthy kidneys remove wastes and excess fluid from the blood. Blood tests show whether the kidneys are failing to remove wastes. Urine tests can show how quickly body wastes are being removed and whether the kidneys are also leaking abnormal amounts of protein. The nephron is the basic structure in the kidney that produces urine. In a healthy kidney there may be as many as 1,000,000 nephrons. Loss of nephrons reduces the ability of the kidney to function by reducing the kidney’s ability to produce urine. Progressive loss of nephrons leads to kidney failure.

 

Serum creatinine. Creatinine is a waste product that comes from meat protein in the diet and also comes from the normal wear and tear on muscles of the body. Creatinine is produced at a continuous rate and is excreted only through the kidneys. When renal dysfunction occurs, the kidneys are impaired in their ability to excrete creatinine and the serum creatinine rises. As kidney disease progresses, the level of creatinine in the blood increases.

Table: Serum Creatinine and Kidney Function

Serum Creatinine (mg/dL)*

Approximate Nephron Loss

Comments

[.6,1.5]

Less than 50% of nephrons lost

Normal Function

(1.5,4.8)

Between 50% and 75% of nephrons lost

Problem

[4.8,10]

Between 75% and 90% of nephrons lost

Bigger Problem

(10,+)

More than 90% of nephrons lost

End Stage Renal Disease

*: milligrams of creatinine per deciliter of serum

Suppose that we sample serum creatinine levels in a random sample of adults. Serum creatinine (as mg/dL) for each sampled subject follows:

15.0, 13.8, 13.5, 13.1, 12.1, 11.1, 10.0, 9.8, 8.1, 7.3, 5.1, 5.0, 4.9, 4.8, 4.0, 3.5, 3.3, 3.2, 3.2, 2.9, 2.5, 2.3, 2.0, 2.0, 1.9, 1.9, 1.7, 1.6, 1.5, 1.5, 1.4, 1.4, 1.3, 1.3, 1.2, 1.2, 1.2, 1.1, 1.1, 1.0, 1.0, 0.9, 0.9, 0.9, 0.8, 0.8, 0.8, 0.7, 0.6, 0.6

Let m denote the sample mean, and sd the sample standard deviation. Compute and interpret the intervals m ± 2sd and m ± 3sd, using Tchebysheff’s Inequalities and the Empirical Rule. Be specific and complete. Show your work, and discuss completely for full credit. 

Case Three

Clinical Trial Sketch

Medicated Cardiovascular Stents

 

Coronary Artery Disease

 

The heart continuously pumps blood enriched with oxygen and vital nutrients through a network of arteries to all parts of the body's tissues. The heart muscle itself needs a plentiful supply of oxygen-rich blood, which is provided through a network of coronary arteries. These arteries carry oxygen-rich blood to the heart's muscular walls (the myocardium). Coronary Artery Disease is the most common cause of heart attacks, which occurs when blood flow to the myocardium is interrupted. Heart attack occurs when blood flow is blocked and tissue death occurs from loss of oxygen, severely damaging the heart. Coronary artery disease is the end result of a complex process commonly called "hardening of the arteries"). This causes blockage of arteries and prevents oxygen-rich blood from reaching the heart.

Angioplasty and Stents

 

A cardiovascular stent props open clogged heart arteries. During an angioplasty, cardiologists use a balloon to push aside heart disease-causing clogs. The opening created by the action of the inflated balloon frequently re-clogs without further intervention. The use of stents is one form of intervention. Stents, a type of metal scaffolding, may be inserted to help keep the artery from re-clogging. Complications from cardiovascular stents can stem from inflammation, clotting and bleeding due to interactions between the stent (usually metallic), the vascular tissue and blood cells. Medicated stents may reduce some of these complications. One accepted approach is to coat stents with drugs that inhibit blood clotting, for example, heparin coated stents are currently FDA licensed. Another approach involves treating the inflammation near the stent site. If the inflammation can be managed, it is thought that clot formation may be reduced. Consider an anti-inflammatory coated stent. Sirolimus is one such drug. A sirolimus coated stent may help control inflammation, thus fighting a new clog, when the artery slowly absorbs some of the drug.

Sketch a comparative clinical trial for Heparin Coated Stents versus Sirolimus Coated Stents in the treatment of patients with Coronary Artery Disease. Make your sketch concise and complete, following the style demonstrated in class, in the second hourly and in case study summaries.

Case Four

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.

4.a):   WidgetCorpsÔ 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 WidgetCorpsÔ.

4.b):   A sample survey design employs a random sample of United Kingdom (England, Wales, Scotland, and Northern Ireland) adult subjects (18 years or older, non-institutionalized). The research objective of the survey is to determine attitudes of Irish subjects regarding Birth Control. Assume that the Survey Instrument is written properly and delivered in an unbiased way.

4.c):   A clinical trial of a new Hepatitis C treatment is designed as follows: subjects are screened for Hepatitis C infection. Those who test positive for Hepatitis C infection are then told of their status, and are offered “free treatment” for Hepatitis C at no cost, and are given no further information. Those who accept the free treatment offer are then randomly assigned to either a Placebo, or to the New Treatment Plan.

 

4.d):   The objective of a sample survey is to study the attitudes of urban residents of the United States regarding federal programs, taxation and spending. A random sample of urban business owners is employed in this design. Assume that there are no problems with the wording and delivery of the survey instrument.