Answer Happy

22 20 18. 16 O Year 1 (1990) 2 3 4 5 6 7 8 8 9 10 9 10 (1999) (a) Construct a scatterplot of these data. y Number of Transplants (in thousands) LUSE SALT 2 15.0 15.7 4 16.1 17.6 18.3 19.3 20.0 20.3 21.4 21.8 6 8 10 X y 22 20 18. 16 O 2 4 (c) Compute the 10 residuals. (Round your answers to three decimal places.) Year Residual 1 2 3 4 5 6 7 6 (b) Describe how the number of transplants performed has changed over time from 1990 to 1999. O From 1990 to 1999 the number of transplants decreased, decreasing less over time. O From 1990 to 1999 the number of transplants increased, increasing less over time. O From 1990 to 1999 the number of transplants increased at a roughly constant rate. O From 1990 to 1999 the number of transplants increased, increasing more over time. O From 1990 to 1999 the number of transplants decreased, decreasing more over time. O From 1990 to 1999 the number of transplants decreased at a roughly constant rate. 8 10 X y 22 20 18 16 . 2 4 6 8 10 X y 22 20 18 16 O Find the equation of the least-squares regression line that describes the relationship between y = number of transplants performed and x = year. (Round your values to four decimal places.) 2 4 6 8 10 X
Construct a residual plot. Residual 0.4 0.2 O 0.0 -0.2 -0.4 . 2 4 6 8 10 X Residual 0.4 O 0.2 0.0 -0.2 -0.4 2 4 6 8 10 X Residual 0.4 O 0.2 0.0 -0.2 -0.4 . 2 O There is more spread on the right side of the residual plot, indicating that a straight line model would be inappropriate. O There are significantly more negative than positive residuals, indicating that a straight line model would be inappropriate. 4 6 8 Residual 0.4 X 10 O 0.2 0.0 -0.2 -0.4 2 d) Are there any features of the residual plot that indicate that the relationship between year and number of transplants performed would be better described by a curve rather than a line? Explain. O There are significantly more positive than negative residuals, indicating that a straight line model would be inappropriate. Ⓒ There is no strong enough pattern in the residual plot to indicate that a straight line model would be inappropriate. O There is more spread on the left side of the residual plot, indicating that a straight line model would be inappropriate. 4 6 8 X 10