The stability of a vehicle, such as a truck, can be measured using a simplified static model as follows:

Stability =

T 2H where T is the nonrandom truck width (i.e., center of the right front tire to the center of the left front tire), and H is the random location of the center of gravity of the vehicle from street level. As the ratio approaches a mean limit L = 1.0, the tendency for the vehicle to roll is increased. Assuming that H and L are random variables with coefficients of variations of 0.15 and 0.1, respectively, perform parametric analysis by assessing failure (rollover) probabilities as functions of typical T (5 to 7 ft)

and mean H (2 to 4 ft) values with mean L = 1.0. Assume

(a) normal and

(b) lognormal probability distributions for all the random variables.