Question

Monitors manufactured by TSI Electronics have life spans that have a normal distribution with a standard deviation of 1200 hours and a mean life span of 18,000 hours. If a monitor is selected at random, find the probability that the life span of the monitor will be more than 16,800 hours. Round your answer to four decimal places.

Answer 1

Answer: 0.8413

Explanation:

Explanation:

Let x be a random variable that represents the life span of monitors manufactured by TSI Electronics .

Also Monitors manufactured by TSI Electronics have life spans that have a normal distribution with

`\mu=18000` hours

`\sigma=1200` hours

∵
`z=(x-\mu)/(\sigma)`

Then for x= 16,800 hours,

`z=(16800-18000)/(1200)=-1`

The probability that the life span of the monitor will be more than 16,800 hours. :-

`P(x>16800)=P(z>-1)=1-P(z\leq-1)\\\\=1-(1-P(z\leq1)\\\\=P(\leq1)= 0.8413447\approx 0.8413`

Hence, he probability that the life span of the monitor will be more than 16,800 hours = 0.8413