Exam 14: Censuses, Surveys, Polls, and Studies: the Joys of Collecting Data

A glass of wine a day is often said to be beneficial to the health and well being of women over 55 years old. Suppose that a study is done which has 2000 participants. Half of the participants are women Who are over 55 years old who drink between one and two glasses of expensive wine each day, while The other half of the participants are women who are over 55 years old who do not drink wine. The Researchers find that after two months of monitoring these women, the group that drinks wine on aDaily basis has significantly fewer health problems than the other group. What variable is most likely Confounding the results of this study?

Refer to the following situation. In order to determine the effects of a new high carbohydrate diet intended to treat Depression of prisoners at maximum security prisons, a researcher conducts a study. Five hundred inmates at the Burlington Maximum Security Penitentiary are selected To participate in the study. The researcher puts the 400 inmates not in solitary Confinement on the new diet. The 100 inmates in solitary confinement are given their Regular meals. The 400 inmates on the new diet are not aware that they being Studied or that their diet has been modified, but have many fewer reported cases of Depression after 30 days. What is the population of interest in this study?

Explain the difference between a census and a survey.

Associated Press - In order to determine how American undergraduate college Students feel about eliminating spring break in order to finish spring term a week Early, a survey was conducted. Two hundred undergraduate students from the University of Miami (FL) were interviewed. Both of the interviewers hired to conduct The survey were told to interview 25 freshmen, 25 sophomores, 25 juniors, and 25 Seniors. Of the 200 students interviewed, 20% were in favor of the elimination of Spring break, 70% were opposed, and 10% had no opinion -Refer to the situation described above; what type of sampling method was used to gather the sample?

A consumer reports group is interested in which medicine works the best. The researchers take 100 volunteers who experience regular head-aches and who are currently not taking any medications. The Researcher split them into four groups of 25 individuals. Group 1 receives four 100-mg doses of Excedrin each day, group 2 receive four 100-mg doses of Tylenol each day, group 3 receives four 100-Mg doses of Advil each day, and group 4 receives four 100-mg doses of a sugar pill each day. After One week, the researchers compare the number of reported head-aches. If both the individuals in each Group and the researchers monitoring them were unaware of who was receiving which drug, then this Study is said to be

A math student is interested in counting the number of jelly beans in a jar. The student opens the jar and removes 40 jelly beans. She places a distinctive mark on each bean and places it back in the jar. After thoroughly shaking the jar, she reaches in and removes 65 jelly beans of which 10 are marked. Using the techniques of capture-recapture, estimate the number of jelly beans in the jar. Give your answer rounded to the nearest whole number.

A Vermont farmer has four different types of cows on his farm, Ayrshire, Friesian, Galloway, and Jersey. The farmer wants to determine the average amount of milk produced by her cows, so she chooses the first ten cows that she sees when she enters her barn and records the amount of milk that each produces in a week. Is this an example of random sampling? Explain.

A factory that produces flour tortillas makes a total of 50,000 tortillas in a batch. A batch is successful and can be shipped to a customer if no more than 8000 of the tortillas are torn. The quality control agent for the company randomly picks 600 tortillas from the batch and finds that 90 are torn. Based on the technique of single-estimation, is the batch successful? Explain using statistics.

Associated Press - In order to determine how American undergraduate college Students feel about eliminating spring break in order to finish spring term a week Early, a survey was conducted. Two hundred undergraduate students from the University of Miami (FL) were interviewed. Both of the interviewers hired to conduct The survey were told to interview 25 freshmen, 25 sophomores, 25 juniors, and 25 Seniors. Of the 200 students interviewed, 20% were in favor of the elimination of Spring break, 70% were opposed, and 10% had no opinion -Refer to the situation describedabove 1; what is the sampling frame for this study?

New Voting Machines Get Towns' Vote Associated Press - Vermont has long been known as being very stubborn and slow to change. However, in lieu of the voting scandals that erupted after the two most recent presidential elections, registered voters in Vermont were demanding something new. State voting officials have installed high-tech electronic voting machines in every region across the state, and people couldn't be happier. From a list of all individuals filing a Vermont State Income tax form, a total of 1000 individuals were randomly selected and contacted by state officials to take part in a survey on the new machines. Of the 845 who responded to the survey, 636 gave favorable reviews while the remaining 209 were still skeptical. "Times are a changing, and for some people it may take a little longer than others!" exclaimed one enthusiastic supporter. -Refer to the situation described above ; how large was the sample?

A math student is interested in counting the number of jelly beans in a jar. The student opens the jar and removes 45 jelly beans. She places a distinctive mark on each bean and places it back in the jar. After thoroughly shaking the jar, she reaches in and removes 80 jelly beans of which 12 are marked. Using the techniques of capture-recapture, estimate the number of jelly beans in the jar. Give your Answer rounded to the nearest whole number.

A researcher was interested in whether different types of music have different effects on an individual's appetite. The researcher randomly breaks his psychology class into two groups each containing 100 students. The first group is told to arrive at the testing facility at 9:00 AM, right after breakfast has ended. The students in the first group are placed in a room with snacks and instructed sit quietly and listen to rock-n-roll music. The second group is told to arrive at the testing facility at 11:00 AM, right before lunch starts. The students in the second group are placed in a room with snacks and instructed sit quietly and listen to hip-hop music. The researchers measure the amount of food eaten by each group and they find that the group listening to the hip-hop music ate significantly more food than the group listening to rock-n-roll music. What variable is most likely confounding this study's results?

A factory that produces corn tortillas makes a total of 40,000 tortillas in a batch. A batch is successful and can be shipped to a customer if no more than 5,000 of the tortillas are torn. The quality control Agent for the company randomly picks 400 tortillas from the batch and finds that X are torn. Based on The technique of single-estimation, what value of X would make the batch not successful?

Explain the difference between blind and double blind in regards to case-controlled studies.

8% of college students smoke cigarettes. You make this conclusion after spending 4 weeks observing students coming and going from the student-recreation center. This value of 8% is called a what?

Forty college students take part in a study on exercise and lung capacity. Twenty of the students are members of the college's swim team who exercise daily while the other twenty members are student volunteers who do not exercise on a regular basis. Two students on the swim team state that they smoke cigarettes on a regular basis while eight of the students who do not exercise state the same. The study finds that the lung capacity of the students who exercise is almost two times greater than the lung capacity of the students who do not exercise. What variable is most likely confounding this study's results?

Refer to the following article. New Voting Machines Get Towns' Vote Associated Press - Vermont has long been known as being very stubborn and slow to change. However, in lieu of the voting scandals that erupted after the two most recent presidential elections, registered voters in Vermont were demanding something new. State voting officials have installed high-tech electronic voting machines in every region across the state, and people couldn't be happier. From a list of all individuals filing a Vermont State Income tax form, a total of 1000 individuals were randomly selected and contacted by state officials to take part in a survey on the new machines. Of the 845 who responded to the survey, 636 gave favorable reviews while the remaining 209 were still skeptical. "Times are a changing, and for some people it may take a little longer than others!" exclaimed one enthusiastic supporter. What is the population of interest in this study?

New Voting Machines Get Towns' Vote Associated Press - Vermont has long been known as being very stubborn and slow to change. However, in lieu of the voting scandals that erupted after the two most recent presidential elections, registered voters in Vermont were demanding something new. State voting officials have installed high-tech electronic voting machines in every region across the state, and people couldn't be happier. From a list of all individuals filing a Vermont State Income tax form, a total of 1000 individuals were randomly selected and contacted by state officials to take part in a survey on the new machines. Of the 845 who responded to the survey, 636 gave favorable reviews while the remaining 209 were still skeptical. "Times are a changing, and for some people it may take a little longer than others!" exclaimed one enthusiastic supporter. -Refer to the situation described above ; what is the sampling frame for this study?

determine the effects of a new high carbohydrate diet intended to treat Depression of prisoners at maximum security prisons, a researcher conducts a study. Five hundred inmates at the Burlington Maximum Security Penitentiary are selected To participate in the study. The researcher puts the 400 inmates not in solitary Confinement on the new diet. The 100 inmates in solitary confinement are given their Regular meals. The 400 inmates on the new diet are not aware that they being Studied or that their diet has been modified, but have many fewer reported cases of Depression after 30 days. -Refer to the situation described above ; what is the control group for this study?

To perform a statistical study on whether or not local business have a Facebook webpage, your Statistics class uses a local phonebook to contact 200 randomly picked business. You ask each Business if they have a Facebook page that you could visit. Your class finds that 45% of the sampled Businesses have Facebook pages. In this study, the sampling frame is what?