Why is non-response a problem in surveys?Ģ2. Does anything about this poll lead you to question its conclusion?Ģ0.
The study was conducted by the Almond Growers Association, and was based on a randomized survey asking people about their consumption of various foods, including almonds, and also about their satisfaction with different aspects of their life. You read a newspaper article reporting that eating almonds leads to increased life satisfaction. Does this improvement prove that a longer school day improves student achievement?ġ9. At the end of one year, student performance on statewide tests had increased by ten percentage points over the previous year. Students who wished to attend this high school were required to sign contracts pledging to put forth their best effort on their school work and to obey the school rules if they did not wish to do so, they could attend another high school in the district. A high school increased the length of the school day from 6.5 to 7.5 hours. Assuming both followed proper sampling procedures and did their calculations correctly, what is a likely explanation for this discrepancy?ġ8. One researcher finds that 84 percent of the children in her sample are up to date, and the other finds that 86 percent in his sample are up to date. Two researchers studying vaccination rates independently draw samples of 50 children, ages 3–18 months, from a large urban area, and determine if they are up to date on their vaccinations. Do you think that those who participate in this poll are representative of all football fans in America?ġ7. Viewers vote by calling a number displayed on the television screen and telling the operator which team they think will win. A popular American television sports program conducts a poll of viewers to see which team they believe will win the NFL (National Football League) championship this year. The manager of a department store decides to measure employee satisfaction by selecting four departments at random, and conducting interviews with all the employees in those four departments. Describe how the chance of being selected will change over the course of drawing the sample.ġ5. A manager wants to draw a sample, without replacement, of 30 employees from a workforce of 150. Describe how you might draw a stratified sample of students from a college, where the strata are the students’ class standing (freshman, sophomore, junior, or senior).ġ4. Describe how you might draw a random sample of 30 students from a lecture class of 200 students.ġ3. What proportion of nurses have ten or fewer years of experience?ġ2. What proportion of nurses have five or more years of experience?ġ1. Fill in the blanks in the table and round your answers to two decimal places for the Relative Frequency and Cumulative Relative Frequency cells. Their answers are summarized in the following (incomplete) table.ĩ. A survey of a random sample of 100 nurses working at a large hospital asked how many years they had been working in the profession. Use the following information to answer the next three exercises. concerning their plans for future education and employment, and found that 50 percent were planning to attend a 4-year college or university in the following year. federal government had the means to survey all high school seniors in the U.S. Fifty percent answer yes to this question that fifty percent is a:Ĩ. One question asks whether they are planning to attend a four-year college or university in the following year. federal government conducts a survey of high school seniors concerning their plans for future education and employment. Describe a situation in which you would calculate a parameter, rather than a statistic.ħ. “Number of visits per week” is what kind of data?Ħ. What kind of a sampling design is this?ĥ.
They decide to ask every tenth customer on a specified day to complete a short survey including information about how many times they have visited the club in the past week.Ĥ. A health club is interested in knowing how many times a typical member uses the club in a week. Use the following information to answer the next two exercises. 1.2: Data, Sampling, and Variation in Data and Sampling
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