Answer:
Option B) 0.0013
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 1000 hours
Standard Deviation, σ = 50 hours
We are given that the distribution of life of bulb is a bell shaped distribution that is a normal distribution.
Formula:
[tex]z_{score} = \displaystyle\frac{x-\mu}{\sigma}[/tex]
P(bulb would last longer than 1150 hours)
[tex]P( x > 1150) = P( z > \displaystyle\frac{1150 - 1000}{50}) = P(z > 3)[/tex]
[tex]= 1 - P(z \leq 3)[/tex]
Calculation the value from standard normal z table, we have,
[tex]P(x > 1150) = 1 - 0.9987 = 0.0013[/tex]
0.0013 is the probability that a randomly selected bulb would last longer than 1150 hours.
Thus, the correct answer is
Option B) 0.0013
