1) Determine whether the evaluated group is a population or a sample. a) Based on a randomly selected group of 500 patients with high cholesterol, it was found that 67% have heart disease. Is this a population or a sample; explain your answer. Population, because it is the study of a number of people for a particular study. b) An investigation of 150 randomly selected local restaurants concluded that 42% of local restaurants have serious health code violations. Is this a population or a sample; explain your answer. Sample, because it is the study of a much smaller group of people.
2) Determine whether the given value is a statistic or a parameter. a) A researcher determines that 42.7% of all downtown office buildings have ventilation problems. Is this a statistic or a parameter; explain your answer. Parameter, because it consist of the study of a specific number of population. b) After taking the first exam, 15 of the students dropped the class. Is this a statistic or a parameter; explain your answer. Statistics, because it is an example of numbers founded by consolidating raw data.
3) Identify the type of sampling used. a) A tax auditor selects every 1000th income tax return that is received. What type of sample is this and why? This is an example of population parameter because these are the characteristics of the entire populations that correspond to the sample statistics. b) The name of each contestant is written on a separate card, and the cards are placed in a bag with three names being picked from the bag. What type of sample is this and why? This is a sample statistics because a percentage of income tax return received measures of sample from raw data collected.
4) Is the study experimental or observation and why? a) A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided. This is an example of observation study because it is the measurement of a specific characteristic without the influence of modifying the outcome.
5) Select the study that is most appropriate and explain why it is most appropriate for the study. a) Is the aspirin produced by a particular pharmaceutical company better than that of a competitor at relieving headaches?
Which of the following would best be used to study this: 1) a case-controlled observation; 2) an observation; 3) a double-blind experimental procedure; and 4) and experimental procedure. This is an example of an observation study because to determine which pharmaceutical company produces the best headache reliever there has to be an observance of the two.
1) Identify the following variables as either qualitative or quantitative and explain your answers. a. The number of people on a jury. Quantitative, because it deals with numbers b. The color of your house. Qualitative, because it deals with category, non-numerical.
2) Identify the number as either continuous or discrete and explain your answers. a. The average height of all freshmen entering college in a certain year is 68.4 inches. Discrete, because the height of all freshmen can be a whole number and/or only integer and half-integer value. b. The number of limbs on a 2-year-old oak tree is 21. Continuous, because the number of climbs can take on any value in a given interval.
3) Determine which of the four levels of measurement is most appropriate and explain your answer. a. Temperatures in degrees Fahrenheit of the ocean at various depths. Interval, because the data varies at certain depths and the temperatures could be different. b. The rank of individuals in the military. Ordinal, because individuals in the military can be arranged in some type of order by rank. c. The number of people with blue, brown and red hair in a classroom. Nominal, because hair color cannot be ranked but can be categorized by the color.
4) Determine the following (show your work): a. The speed of a new microprocessor is 800MHZ, but a new test of its speed gives a measurement of 820MHZ. What is the absolute error? What is the relative error? The absolute error is -20MHZ (800-820= -20), the relative error is 2.44MHZ (-20/820 * 100% = 2.44) b. Convert 1/16 to a percent 0.063 (1/16=0.063)
c. Convert 0.45 to a percent 45% d. Humanities majors spend an average of $115 per course on books. Mathematics majors spend an average of $70 per course on books. What is the percent difference between the two amounts relative to the amount for mathematics majors (round to the nearest percent)? 127.87 (1.56/1.22*100=127.87) e. Suppose that the cost of a statistics text was $50 in 1985 and is $100 in 2000. What is the “Statistics Text Index” number, rounded to the nearest tenth, for the 2000 edition with the 1985 price as the reference value? 200 (100/50*100=200) From Chapter One
1) Focus on Public Health—On page 51 and 52 of the text, it discusses the Harvard Nurses’ Health Study, which is a very well-known study that has been conducted for a number of years. Answer discussion question two at the back of the article.
The Harvard Nurses’ Health Study is an observational study because they are taking surveys and then compiling the data into practical information. They are not actually performing tests on these women that have participated in the study. Dr. Frank E. Speizer decided to study the long term effects of oral contraceptives. He surveyed nurses because he believed that their medical training would prove a more accurate outcome than that of the general public.
Dr. Speizer sent questionnaires out to approximately 370,000 nurses, whereas more than 120,000 nurses participated. Early findings focused on the effects of oral contraceptives and smoking on major illnesses in women. As time progressed, the study broadened to look at the effects of dietary and other lifestyle factors on women’s health. The nurses in the study responded to questionnaires sent every other year, faithfully recording answers to detailed questions about their illnesses, vitamin intake, sense of well-being, amount of physical exercise, and consumption of meat and various fruits and vegetables (JNCIJ National cancer Institute, 2000).
The study found that the vast majority of heart attacks in women are preventable through relatively simple lifestyle modifications—exercising regularly, maintaining healthy weight, and making dietary changes such as reducing saturated fats (found in meat and high-fat dairy products like butter) and trans fatty acids (found in baked goods containing partially hydrogenated vegetable oils, such as pastries), increasing fiber and fruits and vegetables, and not smoking.
Since 1976, for example, the researchers have found far more use of combined hormones (estrogen plus progesterone) compared with estrogen alone, a reduction in red meat consumption, and weight gain among the nurses. And it appears that these changes can have important effects on a woman’s health: Combined hormone use is associated with an increased risk of breast cancer; lower red meat intake is associated with lower colon cancer risk; and weight gain is associated with increased risks of several major diseases—heart disease, stroke, adult-onset diabetes, postmenopausal breast cancer, and colorectal cancer (JNCIJ National cancer Institute, 2000).
It would be possible to gather similar information by carrying out an experimental research as some critics suggest as long as it is done in an ethical way such as informing the nurses and as long as the nurses were willing to submit themselves to the testing.
“The uniqueness of the Nurses’ Health Study is that it began a long time ago and because of the foresight of the researchers they have the opportunity to evaluate a lot of risk factors.” “Over time they have incorporated a lot of different elements and modified the questionnaire to address new topics (JNCIJ National cancer Institute, 2000).
From Chapter Two
2) Focus on Economics—On page 86 and 87, the article looks at an important issue to everyone—the economy. In particular it is focusing on whether our standard of living is improving. Answer discussion question one at the back of the article.
As prices for goods and services that we consume increase, inflation is the result. The inflation rate is used to measure the rate of change in the overall price level of goods and services that we typically consume. Inflation gives a consensus or aggregate measure of the price changes occurring for a number of different goods and services. When we look at individual goods, price changes often vary greatly. During the past decades the price of goods such as automobiles, gasoline, movies, health care, and housing have increased significantly. In contrast, the price of calculators and computing power has decreased substantially.
Over time we often pay more for a good. For example, the price of a Chrysler LeBaron convertible in 1995 to its price in 1985. However, along with the price increase have come substantial improvements in quality. After putting out dismal products in the 1980s, Chrysler made substantial quality improvements in the 1990s. The modern LeBaron buyers enjoy features such as CD stereo players, safety air bags, and a number of other quality improvements that add to the car's value. According to the CPI, we pay more for the LeBaron, contributing to inflation.
Adjusting for quality improvements, the price has not increased nearly as much (Sachs & Warner, 1995). Although the prices of some goods have increased over time, the prices of others have consistently fallen, especially when measured in terms of the labor required to purchase that good. In 1908 is took 4,696 hours in terms of factory wages to purchase an automobile. By 1970, the hours required by the average factory worker to buy a new car had fallen to 1,397 hours. The price in terms of factory hours continued to decrease to 1,365 hours by 1997. Although the absolute price of a new car has steadily risen over time, in terms of labor effort prices have fallen, and the typical 1997 model boasted significant quality improvements over its 1970 counterpart (Sachs & Warner, 1995).
Based upon these examples, I agree with economist the CPI overstates the true effects of inflation. Because the cost of living fluctuates, CPI changes base upon changes in prices of particular items at particular stores. CPI tracks changes in such particular items purchase by consumers at any given time (Bennett, Jeffrey, 2009. p 76).