MATH-221 Week 7 Homework: Statistics for Decision-Making (Extra Version) | 100% CORRECT ANSWERS

(CO 6) The coefficient of determination is represented by what notation? β ρ Correct! r2 r See text page 499 (CO 6) Two variables have a positive linear correlation. Does the independent variable ...

(CO 6) The coefficient of determination is represented by what notation? β ρ Correct! r2 r See text page 499 (CO 6) Two variables have a positive linear correlation. Does the independent variable increase or decrease as the dependent variable increases? Correct Answer Independent variable increases Independent variable decreases Independent variable would remain the same Cannot determine from information given (CO 6) Find the regression equation for the following data set x 245 187 198 189 176 266 210 255 y 50 54 55 78 44 41 51 60 Correct! ŷ = -0.09x + 74.17 ŷ = 74.17x – 0.09 cannot be determined ŷ = 0.09x – 74.17 See text pages 487-488 (CO 6) A student wants to determine if a higher quality diet will improve their grade point average. Which variable would be the response variable? The number of classes taken Correct! Their GPA (CO 6) A value of the dependent variable that corresponds to the value of xi would be given the notation of: y1 b Correct! m See text pages 486-487 (CO 6) The graph for a linear regression crosses the y axis in negative values. Where would the y-intercept of the regression line be located on the y-axis? Correct! Below 0 To the left of 0 (CO 6) What would be the notation for the mean of the y values? Correct! ȳ b (x, y) yi See text pages 486-487 (CO 6) Find the regression equation for the following data set x 9 1 5 2 4 13 19 y 1 2 8 3 7 9 12 ŷ = 2.68x - 0.44 Correct! ŷ = 0.44x + 2.68 See text pages 486-487 (CO 6) A data set whose original x values ranged from 28 through 49 was used to generate a regression equation of ŷ = 2.9x – 34.7. Use the regression equation to predict the value of y when x=56. Correct Answer Meaningless result 318.7 121.1 127.7 See text page 489 (CO 6) A data set whose original x values ranged from 241 through 290 was used to generate a regression equation of ŷ = -0.06x + 9.8. Use the regression equation to predict the value of y when x=240. Correct Answer Meaningless result 24.2 See text page 489 (CO 6) A data set whose original x values ranged from 38 through 65 was used to general a regression equation of ŷ = -4.4x + 2.6. Use the regression equation to predict the value of y when x=62. -275.4 Meaningless result Correct Answer -270.2 275.4 (CO 6) If the linear correlation coefficient is 0.587, what is the value of the coefficient of determination? Correct! 0.294 -0.345 See text page 499 (CO 6) If the linear correlation coefficient is -0.328, what is the value of the coefficient of determination? 0.656 Correct Answer 0.108 -0.164 -0.108 (CO 6) If the coefficient of determination is 0.276, what percentage of the data about the regression line is explained? 72.4% Correct Answer 24.2% 32.4% (CO 6) If the coefficient of determination is 0.326, what percentage of the data about the regression line is unexplained? 65.2% 32.6% Correct! 67.4% 10.7% (CO 6) If the independent variables explained less than 20% of the variation in the dependent variables, which of the following would be true? There are two independent variables Correct! The coefficient of determination is below 0.2 (CO 6) The equation used to predict how tall a kitten will be as an adult is ŷ = 4.5 + 0.6x1 + 0.3x2, where x1 is the height of the sibling and x2 is the height of the mother. Use this equation to predict the height of a kitten whose sibling is 41.3 inches tall and whose mother is 44.9 inches tall. 58.65 inches 53.61 inches 43.83 inches Correct! 42.75 inches (CO 6) The equation used to predict how many days it takes a 15-year old to read the first Harry Potter book is ŷ = 1.5 + 2.82x1 – 1.04x2 days, where x1 weekly hours of other activities and x2 is the reading grade level. Use this equation to predict how many days it will take to read this book for someone with 10.3 weekly hours of other activities and a 10.5 reading grade level. Correct! 17.6 days 20.8 days 20.4 days