Respuesta :
Answer:
2.228%
Step-by-step explanation:
Average life = 2400 hours
So, [tex]\mu = 2400[/tex]
[tex]\sigma = 300[/tex]
An average person listens to music for 1,000 hours in a year
So, An average person listens to music in 3 years= [tex]3 \times 1000 = 3000[/tex] hours
Now we are supposed to find the probability that the component lasts for more than 3 years
[tex]z=\frac{x-\mu}{\sigma}[/tex]
[tex]z=\frac{3000-2400}{300}[/tex]
[tex]z=2[/tex]
So,P(z<3000 hours or 3 years)=P(z<2)=0.9772
So,P(z>2)=1-0.9772=0.0228 or [tex]0.0228 \timesd 100 = 2.228 \%[/tex]
Hence the probability that the component lasts for more than 3 years is 2.228%