Decisive set method [32] A fuzzy approach
Modified subgradient method [32]
A fuzzy approach
Zimmermann’s extended approach [15]
An IF approach
Our proposed approach
x 1 = 1.690331
x 1 = 1.45804
x 1 = 1.333333
x 1 = 1.99453
x 2 = 0.0
x 2 = 7.8 × 10 − 8
α = 0.5556
α = 0.90
β = 0.142
β = 0.09
Z * = 1.690331
Z * = 1.45804
Z * = 1.333333
Z * = 1.99453