Table 5.
ANOVA.
| Model | Sum of squares | df | Mean square | F | Sig. | |
|---|---|---|---|---|---|---|
| 1 | Regression residual total | 184931.762 | 6 | 30821.960 | 8.040 | 0.000a |
| 203179.171 | 53 | 3833.569 | ||||
| 388110.933 | 59 | — | ||||
| 2 | Regression residual total | 184880.7906 | 5 | 36976.181 | 9.825 | 0.000b |
| 203230.1027 | 54 | 3763.519 | ||||
| 388110.933 | 59 | — | ||||
| 3 | Regression residual total | 179069.936 | 4 | 44767.484 | 11.779 | 0.000c |
| 209040.998 | 55 | 3800.745 | ||||
| 388110.933 | 59 | — | ||||
| 4 | Regression residual total | 170715.448 | 3 | 56905.149 | 14.658 | 0.000d |
| 217395.486 | 56 | 3882.062 | ||||
| 388110933 | 59 | — |
aPredictors: average number of customers in a week, age of facility (beauty salon), number of services, temperature (°C), academic qualification, and years of working experience. bPredictors: average number of customers in a week, age of facility (beauty salon), number of services, temperature (°), and academic qualification. cPredictors: average number of customers in a week, age of facility (beauty salon), number of services, and temperature (°C). dPredictors: average number of customers in a week, age of facility (beauty salon), and number of services. eDependent variable: formaldehyde concentration (CL (μg/m3)).