Q$.23$

The article "Reliability$-$Based Service$-$Life Assessment of Aging Concrete

Structures" $($J$.$ Structural Engr., $1993)$ suggests that a Poisson process can

be used to represent the occurrence of structural loads over time. Suppose

the mean time between occurrences of loads is $0\mathrm{.}5$ year.

$($i$)$ How many loads can be expected to occur during a $2-$year period?

$($ii$)$ What is the probability of more than five loads in a $2-$year period?

$($A$)4$ loads, $P(x>5)=0\mathrm{.}371$

$($B$)2$ loads, $P(x>5)=0\mathrm{.}371$

$($C$)4$ loads, $P(x>5)=0\mathrm{.}215$

$($D$)2$ loads, $P(x>5)=0\mathrm{.}215$