The diameters of ball bearings produced in a manufacturing process can be described using a uniform distribution over the interval 6.5 to 8.5 millimeters. Any ball bearing with a diameter of
Over 8.25 millimeters or under 6.75 millimeters is considered defective. What is the probability that
A randomly selected ball bearing is defective?
A).75
B).25
C).50
D)0

Question

Quizplus · Accepted Answer

The uniform distribution means that every outcome in the interval 6.5 to 8.5 millimeters is equally likely. The non-defective range is from 6.75 to 8.25 millimeters, which is 1.5 millimeters out of the total range of 2 millimeters. Therefore, the defective range is 0.25 millimeters on each end (6.5 to 6.75 and 8.25 to 8.5), totaling 0.5 millimeters. The probability of a defective ball bearing is the defective range (0.5 millimeters) divided by the total range (2 millimeters), which equals 0.25 or 25%.

The Diameters of Ball Bearings Produced in a Manufacturing Process