Question

Please show all your work!!

In a certain process, steel bars are manufactured and subjected to a torsion test. Bars are considered acceptable if they support at least 15 lb-ft. Currently the process produces bars that support on average 15.23 lb-ft with a variance of 0.04 lb-ft ^ 2

a)what proportion of the bars will not be able to meet the specifications

b)if we take a sample of 50 bars, how many are expected to fail the test

c)if we wish that no more than 5% of the bars fail the specification, where we must place the average

d)If we select a bar at random and know that it meets the specification, what is the probability that it is above 15.2 lb-ft?

e) If 20 lots are removed from a batch with thousands of bars and the test is rejected and the batch is rejected if any of these fails the test, what is the probability of rejecting the batch?

Answer 1