Exam 1: Data Collection

Determine the level of measurement of the variable. -ranking (first place, second place, etc.) of contestants in a singing competition

Determine what type of observational study is described. Explain. -A researcher wanted to determine whether women with children are more likely to develop anxiety disordersthan women without children. She selected a sample of 900 twenty-year old women and followed them for atwenty-year period. At the start of the study, none of the women had children. By the end of the study 53% ofthe women had at least one child. The level of anxiety of each participant was evaluated at the beginning andat the end of the study and the increase (or decrease) in anxiety was recorded. The researchers analyzed theresults to determine whether there was an association between anxiety and having children.

Determine the level of measurement of the variable. -the year of manufacture of a car

Identify the type of sampling used. -A sample consists of every 30th worker from a group of 1000 workers. What sampling technique was used?

Determine whether the underlined value is a parameter or a statistic. -In a survey conducted in the town of Atherton, 25% of adult respondents reported that they had been involvedin at least one car accident in the past ten years.

Which of the following is not true about factors?

Identify the type of sampling used. -A statistics student interviews everyone in his apartment building to determine who owns a cell phone. Whatsampling technique is used?

A farmer wishes to test the effects of a new fertilizer on her potato yield. She has four equal-sized plots ofland-- one with sandy soil, one with rocky soil, one with clay-rich soil, and one with average soil. She divideseach of the four plots into three equal-sized portions and randomly labels them A, B, and C. The four Aportions of land are treated with her old fertilizer. The four B portions are treated with the new fertilizer, andthe four Cʹs are treated with no fertilizer. At harvest time, the potato yield is recorded for each section of land.What is the response variable in this experiment?

What is a designed experiment?

Classify the variable as qualitative or quantitative. -the weights of cases loaded onto an airport conveyor belt

Quantitative variables classify individuals in a sample according to

Administrators at a large university want to know the average debt incurred by their graduates. Surveys weremailed to 150 graduating seniors asking them to report their total student loan debt. Identify the population,sample, and individuals in the study.

The United States can be divided into four geographical regions: Northeast, South, Midwest, and West. TheNortheast region consists of 9 states; the South region consists of 16 states; the Midwest consists of 12 states;and the West consists of 13 states. If a survey is to be administered to the governors of 10 of the states and wewant equal representation for the states in each of the four regions, how many states from the South should beselected? Round to the nearest whole state.

A researcher wants to study the effects of advertising by female models upon high school boys in smallMidwestern towns. The research methodology calls for selecting several small Midwestern towns that havehigh schools. What is the frame for this study?

Determine what type of observational study is described. Explain. -Vitamin D is important for the metabolism of calcium and exposure to sunshine is an important source ofvitamin D. A researcher wanted to determine whether osteoperosis was associated with a lack of exposure tosunshine. He selected a sample of 250 women with osteoperosis and an equal number of women withoutosteoperosis. The two groups were matched - in other words they were similar in terms of age, diet,occupation, and exercise levels. Histories on exposure to sunshine over the previous twenty years wereobtained for all women. The total number of hours that each woman had been exposed to sunshine in theprevious twenty years was estimated. The amount of exposure to sunshine was compared for the two groups.

Which branch of statistics deals with the organization and summarization of collected information?

Which of the following is not true of statistics?

Identify the type of sampling used. -A travel industry researcher interviews all of the passengers on five randomly selected cruises. What samplingtechnique is used?

Determine the level of measurement of the variable. -time spent playing basketball

Parking at a large university has become a very big problem. University administrators are interested indetermining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. Anadministrator inconspicuously followed 120 students and carefully recorded their parking times. Identify thepopulation of interest to the university administration.