In: Statistics and Probability
DATAfile: CorporateBonds
| Company Ticker | Years | Yield |
| GE | 1 | 0.767 |
| MS | 1 | 1.816 |
| WFC | 1.25 | 0.797 |
| TOTAL | 1.75 | 1.378 |
| TOTAL | 3.25 | 1.748 |
| GS | 3.75 | 3.558 |
| MS | 4 | 4.413 |
| JPM | 4.25 | 2.31 |
| C | 4.75 | 3.332 |
| RABOBK | 4.75 | 2.805 |
| TOTAL | 5 | 2.069 |
| MS | 5 | 4.739 |
| AXP | 5 | 2.181 |
| MTNA | 5 | 4.366 |
| BAC | 5 | 3.699 |
| VOD | 5 | 1.855 |
| SHBASS | 5 | 2.861 |
| AIG | 5 | 3.452 |
| HCN | 7 | 4.184 |
| MS | 9.25 | 5.798 |
| GS | 9.25 | 5.365 |
| GE | 9.5 | 3.778 |
| GS | 9.75 | 5.367 |
| C | 9.75 | 4.414 |
| BAC | 9.75 | 4.949 |
| RABOBK | 9.75 | 4.203 |
| WFC | 10 | 3.682 |
| TOTAL | 10 | 3.27 |
| MTNA | 10 | 6.046 |
| LNC | 10 | 4.163 |
| FCX | 10 | 4.03 |
| NEM | 10 | 3.866 |
| PAA | 10.25 | 3.856 |
| HSBC | 12 | 4.079 |
| GS | 25.5 | 6.913 |
| C | 25.75 | 8.204 |
| GE | 26 | 5.13 |
| GE | 26.75 | 5.138 |
| T | 28.5 | 4.93 |
| BAC | 29.75 | 5.903 |
A statistical program is recommended.
A sample containing years to maturity and yield (%) for 40 corporate bonds is contained in the data file named CorporateBonds.†
(a) Develop a scatter diagram of the data using x = years to maturity as the independent variable.
Does a simple linear regression model appear to be appropriate?
Given the upward trend of the data on the left side of the plot, a linear regression model would predict higher values for the data on the right side of the plot. So, a curvilinear regression model appears to be more appropriate.Since the data on the left and right sides of the plot both trend downward at about the same rate, a linear model is appropriate. Given the downward trend of the data on the left side of the plot, a linear regression model would predict lower values for the data on the right side of the plot. So, a curvilinear regression model appears to be more appropriate.Since the data on the left and right sides of the plot both trend upward at about the same rate, a linear model is appropriate.
(b) Develop an estimated regression equation with x = years to maturity and x2 as the independent variables. (Round your numerical values to two decimal places.)
ŷ =
| Regression Analysis | ||||||
| R² | 0.668 | |||||
| Adjusted R² | 0.650 | |||||
| R | 0.817 | |||||
| Std. Error | 0.958 | |||||
| n | 40 | |||||
| k | 2 | |||||
| Dep. Var. | Yield,y | |||||
| ANOVA table | ||||||
| Source | SS | df | MS | F | p-value | |
| Regression | 68.3011 | 2 | 34.1506 | 37.19 | 1.40E-09 | |
| Residual | 33.9750 | 37 | 0.9182 | |||
| Total | 102.2761 | 39 | ||||
| Regression output | confidence interval | |||||
| variables | coefficients | std. error | t (df=37) | p-value | 95% lower | 95% upper |
| Intercept | 1.02 | |||||
| Years,x | 0.46 | 0.0814 | 5.662 | 1.80E-06 | 0.2958 | 0.6255 |
| x^2 | -0.01 | 0.0026 | -3.964 | .0003 | -0.0155 | -0.0050 |

a)Given the upward trend of the data on the left side of the plot, a linear regression model would predict higher values for the data on the right side of the plot. So, a curvilinear regression model appears to be more appropriate
b)
ŷ = 1.02+0.46*x-0.01*x2