Table 2 Parameters of the dual Weibull distribution models of the overall, male-only, and female-only samples
Parameter | Result* | Bootstrap: 95% confidence interval | ||
|---|---|---|---|---|
Mean* | Lower bound | Upper bound | ||
Model 1: Overall sample (N = 4717) -Log-likelihood = 17,219.28 | ||||
 Scale (η1) | 40.90 | 40.89 | 39.29 | 42.17 |
 Shape (β1) | 7.08 | 7.14 | 5.96 | 8.36 |
 Weight (w) | 0.82 | 0.82 | 0.78 | 0.85 |
 Threshold (θ) | 31.50 | 31.53 | 29.60 | 33.20 |
 Scale (η2) | 20.50 | 20.49 | 19.81 | 21.07 |
 Shape (β2) | 2.89 | 2.89 | 2.79 | 3.01 |
Model 2: Male sample (N = 1701) -Log-likelihood = 6228.31 | ||||
 Scale (η1) | 39.59 | 39.52 | 36.62 | 41.66 |
 Shape (β1) | 6.41 | 6.48 | 5.01 | 7.99 |
 Weight (w) | 0.73 | 0.72 | 0.61 | 0.80 |
 Threshold (θ) | 30.20 | 30.16 | 26.35 | 33.10 |
 Scale (η2) | 21.91 | 21.86 | 20.15 | 23.05 |
 Shape (β2) | 3.35 | 3.36 | 3.16 | 3.62 |
Model 3: Female sample (N = 3016) -Log-likelihood = 10,887.69 | ||||
 Scale (η1) | 41.75 | 41.62 | 39.31 | 43.35 |
 Shape (β1) | 7.62 | 7.66 | 5.69 | 9.72 |
 Weight (w) | 0.86 | 0.86 | 0.82 | 0.89 |
 Threshold (θ) | 32.10 | 31.96 | 29.30 | 34.20 |
 Scale (η2) | 19.63 | 19.60 | 18.83 | 20.26 |
 Shape (β2) | 2.77 | 2.78 | 2.66 | 2.92 |