In a poll, 1,002 adults in a country were asked whether they favor or oppose the use of “federal tax dollars to fund medical research using stem cells obtained from human embryos.” Among the respondents, 47% said that they were in favor. Describe the statistical study
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In a test of the effectiveness of garlic for lowering cholesterol, were treated with garlic in a processed tablet form. Cholesterol levels were measured before and after the treatment. The changes in their levels of LDL cholesterol (in mg/dL) have an average (mean) of . Identify the sample, the population, the sample statistic, and the population parameter in this study.
Fifty adult men in the United States are randomly selected and measured for their body mass index (BMI). Based on that sample, it is estimated that the average (mean) BMI for men is , with a margin of error of . Use the given statistic and margin of error to identify the range of values (confidence interval) likely to contain the true value of the population parameter.
The range of values likely to contain the population parameter is from to .
(Type an integer or a decimal. Use ascending order.)
Based on a recent survey of adults in households, a labor department reported an unemployment rate of %. The margin of error was percentage point.
A researcher wants to determine the percentage given below. Describe how the researcher should apply the five basic steps in a statistical study. (Assume that all the people in the poll answered truthfully.) the percentage of company executives that use jet fuel
Determine whether a census is practical in the situation described. Explain your reasoning. You want to determine the mean height of all basketball players in a country
A company hires independent university scientists to determine whether its new, genetically engineered soybean poses any threat to the environment. Are there sources of bias in this situation?
An engineering student measures the strength of fingers used to type on a newly designed keyboard by testing a friend’s family members.
In a comparison of synthetic oil versus conventional oil, 26 sport utility vehicles are driven with synthetic oil, while 30 station wagons are driven with conventional oil. After being driven for 350 miles, each vehicle is rated on quality of performance. The researchers doing the performance quality ratings are aware of which vehicles receive synthetic oil and which receive conventional oil. Identify any problems that are likely to cause confounding and explain how the problems could be avoided.
Select the sample most representative of the population of interest. An employer wants to determine the importance of health insurance as a benefit to employees.
Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience. To avoid working late, a quality control analyst simply inspects the first 100 items produced in a day.
Identify the type of study most appropriate to the question. What is the mean number of cars waiting for the green light at Main and Empire at rush hour (4:00 PM to 7:00 PM)?
Determine whether the data described below are qualitative or quantitative and explain why.
Determine if the following statement represents a meaningful ratio, so the ratio level of measurement applies. A movie with a 4-star rating is twice as good as one with a 2-star rating.
Determine whether the data described below are qualitative or quantitative and also identify their level of measurement. If the data are quantitative, state whether they are continuous or discrete, and give a brief explanation.
The sticker on a car states that it gets 24 miles per gallon on the highway, but measurements show that its highway mileage is actually miles per gallon. Find the values of the absolute and relative errors.
Express each of the following numbers in all three forms: fraction, decimal, and percentage.
In a certain survey of 1,037 adults, % reported having more than one television at home. Find the actual number of respondents corresponding to the given percentage.
Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. Temperatures of the ocean at various depths.
Two statements are given. Identify the statement for which a ratio of the measurements is meaningful. State “Neither” or “Both” if appropriate.
1The tallest girl on the team is 6’1″, and the shortest is 5’2″.
2The length of the rectangle is 17.2 cm, and the width is 8.2 cm.