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 510 hours. find the probability of a bulb lasting for at most 528 hours. round your answer to four decimal places.

Answer 1

From the calculation that have been done in this question, the probability that the bulb would have to last for at least 528 hours is given as 0.81594

What is probability?

This is the term that is used to refer to the likelihood of something occurring given that we have a pair of events.

The formula that is required to solve for this is given as

x - u / sd

where we have to define the variables as

x = hours that it would last = 528

u = mean = 510

sd = standard deviation = 20 hours

We would have to put these values in  the equation here

528 - 510 / 20

= 0.9

we have the z value from the z test as 0.9

Next we have to check the z score on the z table

P(X ≤ 622)=P(Z ≤ 0.9) = 0.81594

Probability of x<528: 0.81594

Read more on probability here: https://brainly.com/question/25870256

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