Question

Some LCD panels have stuck or "dead" pixels that have defective transistors and are permanently unlit. If a panel has too many dead pixels, it must be rejected. A manufacturer knows that, when the production line is working correctly, the probability of rejecting a panel is .07 of every 500 panels produced. (a) what is the probability that they will reject 37 or more screens in one production day? (b) if the production manager told you that the distribution for a particular run of screens was 2.5 below the mean, about how many screens would you expect were rejected for that day?

Answer 1

Solution:

We are given:

(a) what is the probability that they will reject 37 or more screens in one production day?

Answer:

We have to find

Using the standard normal table we have:

Therefore, the probability that they will reject 37 or more screens in one production day is 0.3632

(b) if the production manager told you that the distribution for a particular run of screens was 2.5 below the mean, about how many screens would you expect were rejected for that day?

Answer:

Using the z-score formula, we have:

Therefore, we would expect 21 screens were rejected for that day.