MATH 221 Week 7 Homework; Statistics for Decision-Making

1. Question:Two variables have a negative linear correlation. Does the dependent variable increase or decrease as the independent variable increases? 2. Question:What does the variable r2 represent? 3. Question:A baseball player wants to determine if the type of bat he uses each year can be used to predict the amount of improvement in his game. Which variable would be the response variable? 4. Question:Two variables have a negative linear correlation. Is the slope of the regression line between these two variables positive or negative? 5. Question:A value of the y-intercept of the regression line would be given the notation of: 6. Question:What would be the notation for the mean of the y values? 7. Question:Which of the following graphs displays the regression equation ŷ=-0.91x + 11.97? 8. Question:Find the regression equation for the following data set 9. Question:A data set whose original x values ranged from 41 through 78 was used to generate a regression equation of ŷ=5.3x – 21.9. Use the regression equation to predict the value of y when x=56. 10. Question:A data set whose original x values ranged from 120 through 351 was used to generate a regression equation of ŷ=0.06x + 14.2. Use the regression equation to predict the value of y when x=110. 11. Question:Find the regression equation for the following data set 12. Question:A data set whose original x values ranged from 137 through 150 was used to generate a regression equation of ŷ=-4.5x + 51. Use the regression equation to predict the value of y when x=141. 13. Question:If the linear correlation coefficient is 0.546, what is the value of the coefficient of determination? 14. Question:If the linear correlation coefficient is -0.156, what is the value of the coefficient of determination? 15. Question:If the coefficient of determination is 0.492, what percentage of the data about the regression line is explained? 16. Question:If the coefficient of determination is 0.394, what percentage of the data about the regression line is unexplained? 17. Question:A regression equation can have more than one ____________ . 18. Question:The equation used to predict how tall a dog will be as an adult is ŷ=4.5 + 0.7x1 + 0.55x2, wherex1is the height of the mother and x2 is the height of the father. Use this equation to predict the height of a puppy whose mother is 45.2 inches tall and whose father is 41.6 inches tall. 19. Question:The equation used to predict how long it will take to receive a package through the mail is ŷ=0.5 + 0.02x1 + 0.85x2 days, wherex1is the distance to travel and x2 is the weight of the package. Use this equation to predict the how long it will take to receive a package that is 145 miles away and weighs 3.8 pounds. 20. Question:The equation used to predict how long a cold will last is ŷ=-1.8 + 0.09x1 + 3.2x2 – 1.9x3, where x1 is person’s temperature on the first day, x2 is number of people seen each day, and x3 is the amount of sleep the person gets. Usethis equation to predict how long a cold will last with a temperature of 100.4 degrees, an average of 6 people seen each day, and 4 hours of sleep