MATH 225N Week 8 Assignment Correlation and Causation Download to Score A

Week 8 Assignment: Correlation and Causation Understand the difference between correlation and causation Question True or False: The more samples taken in a scientific study, the longer the amount of time it will tak ...

Week 8 Assignment: Correlation and Causation Understand the difference between correlation and causation Question True or False: The more samples taken in a scientific study, the longer the amount of time it will take to complete the research on the samples. Although there are other factors that affect study time, such as experience and equipment, increasing the number of samples will cause an increase in research time. Correct! You nailed it. Understand the difference between correlation and causation Question Suppose that a large controlled experiment tests whether caffeine improves reaction times. A very large number of randomly selected participants are randomly given identical-seeming pills with varying doses of caffeine (including none) and then given tests of reaction times under the same conditions. The experiment finds a strong negative correlation between caffeine dose and reaction time. (Note that lower reaction times are better.) Correct answer: There is evidence that caffeine causes lower (better) reaction times. Correlation alone does not prove causation, but this scenario provides more evidence than just correlation between two variables. Since the data were obtained from an appropriately randomized controlled experiment, a correlation can be used as evidence of a causal relationship. Since all other variables were controlled, there is no third variable that could be associated with caffeine that actually causes differences in reaction times. Yes that's right. Keep it up! Interpret the slope and y-intercept of the least squares regression line Question Which of the following situations could have a regression line with a negative yintercept? Select all that apply: Great work! That's correct.  The present value of an insurance policy as a function of the age of the ensured person if the person purchases the policy when he or she is 50 years old.   The number of millions of barrels of oil in an oil field as a function of the number of years the oil field has been in production.  This study source was downloaded by 100000831988016 from CourseHero.com on 01-07-2022 03:17:55 GMT -06:00 https://www.coursehero.com/file/60088499/Week-8-Stats-Assignment-Correlation-and-Causationdocx/  The value of a Fortune-500 company, founded in the year 1990, as a function of the number of years after the year 2010.   The value of a rail locomotive as a function of the number of years since it was put into service. Interpret the slope and y-intercept of the least squares regression line Question Which of the following data sets or plots could have a regression line with a negative slope? Select all that apply. Perfect. Your hard work is paying off �  The number of tons of trash in a landfill as a function of the number of years since the landfill was built.   The number of loads of trash a dump truck hauls per month as a function of the number of years since the dump truck was built.   The number of tons of trash produced in a city as a function of the population.   The number of minutes you will wait to drop off your trash at a landfill as a function of the number of dump trucks at the landfill Correct answer: The slope is related to the increase or decrease of the dependent variable as a function of the independent variable. If the dependent variable can decrease, then the slope can be negative. Understand the difference between correlation and causation Question Suppose that data collected from police reports of motor vehicle crashes show a moderate positive correlation between the speed of the motor vehicle at the time of the crash and the severity of injuries to the driver. Answer the following question based only on this information. True or false: It can be concluded that the faster a motor vehicle is traveling at the time of a crash, the more severe the injuries to the driver are. Well done! You got it right.Correlation does not prove causation. The provided information shows that there is a positive association between speed and severity of injuries, but that information alone is not sufficient to conclude that greater This study source was downloaded by 100000831988016 from CourseHero.com on 01-07-2022 03:17:55 GMT -06:00 https://www.coursehero.com/file/60088499/Week-8-Stats-Assignment-Correlation-and-Causationdocx/ speed causes more severe injuries. Based only on this information, there could be a third variable associated with speed that causes more severe injuries in crashes. That said, the statement "the faster a motor vehicle is traveling at the time of a crash, the more severe the injuries to the driver are" does not imply a causal relationship between speed and severity of injuries. Understand the difference between correlation and causation Question An experiment finds that runners with the longest legs complete a mile run in less time. Identify the relation between leg length and time of a mile run. Leg length and time of a mile run are negatively correlated. A longer leg length is associated with a lower time of a mile run, which implies a negative relationship. There would need to be more evidence to prove causation.Yes that's right. Keep it up! Interpret the slope and y-intercept of the least squares regression line Question Which of the following situations would have data sets or plots that could have a regression line with a positive slope? Select all that apply. Great work! That's correct. Correct answer: The cumulative number of ships launched by ship builders as a function of the number of months since the start of the year The number of cars produced as a function of the number of days since the end of the last strike. The total shipping orders that are backlogged as a function of the number of ships in drydock. The slope is related to the increase or decrease of the dependent variable as a function of the independent variable. If the dependent variable can increase, then the slope can be positive, such as with the cumulative number of ships launched. Interpret the slope and y-intercept o