Question

The life of light bulbs is distributed normally. The standard deviation of the lifetime is 20 hours and the mean lifetime of a bulb is 500 hours. Find the probability of a bulb lasting for between 480 and 526 hours.

Answer 1

Answer:

The probability of a bulb lasting for between 480 and 526 hours=0.74454

Step-by-step explanation:

We are given that

Standard deviation of the lifetime,$\sigma=20$hours

Mean, $\mu=500$hours

We have to find the probability of a bulb lasting for between 480 and 526 hours.

$P(480$

$P(480$

$P(480$

$P(480$

$P(480$

Hence, the probability of a bulb lasting for between 480 and 526 hours=0.74454