WEEK 8 ASSIGNMENT CORRELATION AND CAUSATION CORRECT ANSWERS GRADED A

WEEK 8 ASSIGNMENT CORRELATION AND CAUSATION CORRECT ANSWERS GRADED A True or False: The more samples taken in a scientific study, the longer the amountof 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, increasingthe 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 Correct answer: Correlation alone does not prove causation, but this scenario provides more evidence than just correlation between two variables. Since the data were obtainedfrom 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 causesdifferences 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 y-intercept? 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 50years old. • • The number of millions of barrels of oil in an oil field as a function of thenumber of years the oil field has been in production. • • The value of a Fortune-500 company, founded in the year 1990, as a function of the number of years after the year 2010. •