The amount of drying time for the paint applied to a plastic component part is thought to be uniformly distributed between 30 and 60 minutes. Currently, the automated process selects the part from the drying bin after the part has been there for 50 minutes. The probability that none of three parts picked are still wet when they are selected is approximately 0.04.

Question

Quizplus · Accepted Answer

The probability that a part is not wet when selected after 50 minutes is calculated based on the uniform distribution from 30 to 60 minutes. This means the drying time has a range of 30 minutes, and selecting after 50 minutes gives a 20-minute window where the part is dry. The probability for one part being dry is 20/30 or 2/3. For three parts, the probability that all are dry is (2/3)^3 = 8/27, which is approximately 0.296, not 0.04.

The Amount of Drying Time for the Paint Applied to a Plastic