Question

Of the bolts produced by a factory 2% are defective. In a shipment of 3600 bolts from the factory, the expected number of defective bolts is

• A. $144$
• B. $72$
• C. $36$
• D. $18$

Answer 1

The correct option is B $72$

2% bolts are defective in production. $p=.02$
In a shipment of $3600\left(n\right)$ bolts from the factory, the expected number of defective bolts is

$E\left(X\right)=np=3600\times \left(.02\right)=72$