Answer
0.9497
Work Step by Step
According to items (a) and (b):
$P(too~heavy)=0.0119$ and $P(too~light)=0.0384$
Since the events "too heavy" and "too light" are disjoint events, we can use the Addition Rule for Disjoint Events (page 270):
$P(too~heavy~or~too~light)=P(too~heavy)+P(too~light)=0.0119+0.0384=0.0503$
The event "can be used" is the complement of the event "too heavy or too light".
Using the Complement Rule (see page 275):
$P(can~be~used)=1-P(too~heavy~or~too~light)=1-0.0503=0.9497$
