The article “Monte Carlo Simulation—Tool for Better Understanding of LRFD” (J. of Structural Engr., 1993:

1586–1599) suggests that yield strength (ksi) for A36 grade steel is normally distributed with and .

a. What is the probability that yield strength is at most 40?

Greater than 60?

b. What yield strength value separates the strongest 75%

from the others?

m 5 43 s 5 4.5 3.000 mm m 5 30 s 5 5 s

m 1500 mm 1500 mm 1500 mm 1000 mm 150 mm 1050 mm