MATH220 Elementary Statistics Test 3 Due: Wednesday, July 1, 2020 Answer all of the following question. You are encouraged to use software; however, your answers must provide the information necessary to illustrate your reasoning. Include screenshots (neatly edited). This test assesses material covered in chapters 10 – 12. 1. The table below lists the number of manatee deaths related to encounters with watercraft and natural causes for each of several different years. a. Find the value of the linear correlation coefficient and determine whether there is a significant linear correlation between the two variables. b. Find the equation of the regression line. Let the number of natural deaths represent the response (y) variable. What is the best predicted number of natural deaths in a year with 50 deaths from encounters with watercraft? 2. Many people believe that fatal driving-while-intoxicated (DWI) crashes occur because of casual drinkers who tend to binge on Friday and Saturday nights, whereas others believe that fatal DWI crashes are caused by people who drink every day of the week. In a study of fatal car crashes, 216 cases are randomly selected from the pool in which the driver was found to have a blood alcohol content over 0.10. These cases are broken down according to the day of the week, with the results listed in the accompanying table. At the 0.05 significance level, test the claim that such fatal crashes occur on the different days of the week with equal frequency. Does the evidence support the theory that fatal DWI car crashes are due to casual drinkers or that they are caused by those who drink daily? 3. Samples of head breadths were obtained by measuring skulls of Egyptian males from three different epochs, and the measurements are listed below (based on data from Ancient Races of the Thebaid, by Thomson and Randall-Maciver). Changes in head shape over time suggest that interbreeding occurred with immigrant populations. Use a 0.05 significance level to test the claim that the different epochs do not all have the same mean. What do you conclude?
