Answer:
Jolt can expect to replace 160 units.
Explanation:
given data:
standard deviation 1.7
average lfe of connectors = 18.2 months
number of connectors = 5000
[tex]z(19) = \frac{(19-18.2)}{1.7}[/tex]
z(19) = 0.4706
P(x< 19) = P(z< 0.4706)
P(x< 19) = 0.6810 from z table
therefore 68.1% fails within 19 months.
hence 0.3190 {100-68.1} will fail during that period.
number of unit of Jolt that need to be replace, on average is 0.319*500 = 160 units.