A medium-size crane carries out 2900 lifts per annum. The load in one lift is modelled as a normal random variable with mean of 55 kN and COV of 0.20. The power span of the crane is modelled as a 6-m cantilever with the plastic section modulus Z, which is treated as a normal random variable with mean 2.110-3 m 3 and COV of 0.04. The cantilever is made of steel, whose yield strength, fy, is treated as a lognormal random variable with mean of 370 N/mm2 and COV=0.08. The annual probability of failure of the crane in bending is estimated using Monte Carlo simulation with the limit state function formulated as ( ) G Zf WL X y where W is the load and L=6 m is the length of the power span. The latter should be treated as a deterministic parameter. (a) Perform one simulation trial manually using the following random numbers: u1=0.0197, u2=0.4369 and u3=0.8734. (b) Adapt the Visual Basic code for Monte Carlo simulation provided with the course materials and run the program with sufficient number of simulation trials to ensure that the COV of the Pf estimate is less than 0.05. Use Excel for the calculations.