- Researchers conducted a study to determine whether magnets are effective in treating back pain. Pain was measured using the visual analog scale, and the results given below are among the results obtained in the study. Higher scores correspond to greater pain levels. Is this study an experiment or an observational study?Explain Reduction in Pain Level After Magnet Treatment: n=20,bar (x)=0.486,s=0.959 Reduction in Pain Level After Sham Treatment: n=20,bar (x)=0.444,s=1.42 Choose the correct answer below A. The study is an observational study because the subjects are a simple random sample B. The study is an experiment because the subjects are a systematic sample. C. The study is an observational study because there was no attempt to modify the individuals being studied. D. The study is an experiment because subjects were given treatments.
- Identify the level of measurement of the data and explain what is wrong with the given calculation. In a survey, the responses of respondents are identified as 1 for a "yes", 2 for a "no", 3 for a "maybe", and 4 for anything else. The average (mean) is calculated for 502 respondents and the result is 1.5 The data are at the square level of measurement. What is wrong with the given calculation? A. Such data are not counts or measures of anything, so it makes no sense to compute their average (mean). B. The true average (mean) is 2.1 C. Such data are not counts or measures of anything, so the average (mean) needs to be computed in a different way. D. There is nothing wrong with the given calculation.
- Determine whether the given value is a statistic or a parameter. A homeowner measured the voltage supplied to his home on all 7 days of a given week, and the average (mean) value is 126.3 volts. Choose the correct answer below. A. The given value is a statistic for the week because the data collected represent a sample. B. The given value is a parameter for the week because the data collected represent a sample. C. The given value is a statistic for the week because the data collected represent a population D. The given value is a parameter for the week because the data collected represent a population
- State whether the data described below are discrete or continuous, and explain why The number of people in a theater each night Choose the correct answer below. A. The data are discrete because the data can take on any value in an interval. B. The data are continuous because the data can take on any value in an interval. C. The data are discrete because the data can only take on specific values. D. The data are continuous because the data can only take on specific values.
- Simplify the following expression. -10x^2-3x-9x^2+4+12x square
