In: Statistics and Probability
A large grocery retailer tracks productivity and costs of its facilities closely. Data in the Grocery retailer file were obtained from a single distribution center for a one-year period. Each data point for each variable represents one week of activity. The variables included are total labor hours required to handle a shipment (Y) in the first column, the number of cases shipped (X1) in the second column, the indirect costs of the total labor hours as a percentage (X2) in the third column, and a qualitative predictor called holiday (X3: 1 if holiday week, 0 otherwise) in the last column.
Report the p-value of the t-ratio test for X2. Write down the null and alternative hypothesis for this single slope. State your conclusion (Reject or Fail to reject)?
LaborHours NoShipped IndLaborCost HolidayWeek 4264 305657 7.17 0 4496 328476 6.20 0 4317 317164 4.61 0 4292 366745 7.02 0 4945 265518 8.61 1 4325 301995 6.88 0 4110 269334 7.23 0 4111 267631 6.27 0 4161 296350 6.49 0 4560 277223 6.37 0 4401 269189 7.05 0 4251 277133 6.34 0 4222 282892 6.94 0 4063 306639 8.56 0 4343 328405 6.71 0 4833 321773 5.82 1 4453 272319 6.82 0 4195 293880 8.38 0 4394 300867 7.72 0 4099 296872 7.67 0 4816 245674 7.72 1 4867 211944 6.45 1 4114 227996 7.22 0 4314 248328 8.50 0 4289 249894 8.08 0 4269 302660 7.26 0 4347 273848 7.39 0 4178 245743 8.12 0 4333 267673 6.75 0 4226 256506 7.79 0 4121 271854 7.89 0 3998 293225 9.01 0 4475 269121 8.01 0 4545 322812 7.21 0 4016 252225 7.85 0 4207 261365 6.14 0 4148 287645 6.76 0 4562 289666 7.92 0 4146 270051 8.19 0 4555 265239 7.55 0 4365 352466 6.94 0 4471 426908 7.25 0 5045 369989 9.65 1 4469 472476 8.20 0 4408 414102 8.02 0 4219 302507 6.72 0 4211 382686 7.23 0 4993 442782 7.61 1 4309 322303 7.39 0 4499 290455 7.99 0 4186 411750 7.83 0 4342 292087 7.77 0
The hypothesis being tested is:
H0: β2 = 0
H1: β2 ≠ 0
The p-value is 0.5584.
Since the p-value (0.5584) is greater than the significance level (0.05), we fail to reject the null hypothesis.
Therefore, we cannot conclude that the slope is significant.
R² | 0.678 | |||||
Adjusted R² | 0.659 | |||||
R | 0.824 | |||||
Std. Error | 143.423 | |||||
n | 54 | |||||
k | 3 | |||||
Dep. Var. | Y | |||||
ANOVA table | ||||||
Source | SS | df | MS | F | p-value | |
Regression | 21,69,505.41952067 | 3 | 7,23,168.47317356 | 35.16 | 2.29E-12 | |
Residual | 10,28,507.41381266 | 50 | 20,570.14827625 | |||
Total | 31,98,012.83333333 | 53 | ||||
Regression output | confidence interval | |||||
variables | coefficients | std. error | t (df=50) | p-value | 95% lower | 95% upper |
Intercept | 4,192.6803 | |||||
X1 | 0.0006 | 0.00035117 | 1.844 | .0711 | -0.0001 | 0.0014 |
X2 | -13.5918 | 23.0686 | -0.589 | .5584 | -59.9264 | 32.7429 |
X3 | 627.1743 | 62.4860 | 10.037 | 1.42E-13 | 501.6676 | 752.6811 |