Statistics Week 1-3 Questions & Answers

Statistics Week 1-3 Questions & Answers A 2016 Pew Research poll estimated the proportion of people supporting each presidential candidate in the fall election. They based their estimates on telephone interviews of 2,010 adults living in all 50 U.S. states. They asked each participant which presidential and vice presidential candidate they support, and used that data to calculate the proportions. What is the statistic in this experiment? - ANSWER: The proportions of participants who support each presidential candidate. Remember that the statistic in an experiment is the numerical characteristic of the sample. Therefore, the statistic in this example is the proportions in the sample, the proportions of participants who support each candidate. a bar graph is appropriate for - ANSWER: categorical data where you want to see the absolute quantity and compare between subcategories A biologist samples and measures the length of the fish in a lake. What is the level of measurement of the data? - ANSWER: Ratio This is ratio data because length has a true zero, and ratios of lengths are meaningful. A biologist wants to study the effect of vitamin D enriched food on the weight of adult mice. Would an experimental or observational study design be more appropriate? - ANSWER: An experimental study should be used where the food consumed is the controlled factor. An experimental study should be used because the goal involves a cause and effect relationship. A biology student is interested in the relationship between temperature and germination time for soy beans. The student gets sample seeds from multiple sources and randomly selects 180 seeds from them. Then he sets up three growing stations, one at 20∘C, one at 15∘C, and one at 25∘C. He divides the seeds into three groups of 60 and plants the seeds from each group in a growing station. He records the germination time for each seed. - ANSWER: The study is an experiment. The controlled factor is the temperature.