Independent voltage measurements (μ±σ) of three sensors where μ and σ are the mean and standard deviation of the measurements, respectively are as follows: v₁ = 4.52±0.02 V, v₂ = 4.21±0.20 V, v₃ = 3.96±0.15 V. The measurement uncertainty in v₁ + v₂ + v₃ is _______ V (rounded off to two decimal places).