Home » Posts tagged 'JN2-28-14'
Tag Archives: JN2-28-14
Human error is the most common kind
Permanent Memories has three employess who burn Blu-ray discs. Employee 1 has a 0.002 chance of making an error, employee 2 has a 0.001 chance of making an error, and employee 3 has a 0.004 chance of making an error. The employees burn roughly the same number of discs in a day.
(a) What is the probability that a randomly chosen disc has an error on it?
(b) Given that a disc has an error, what is the probability that employee 1 was the culprit?
(c) Given that a disc has an error and employee 3 was on vacation the day it was burned, what is the probability that employee 2 was the culprit?
[Author Mark Huber. Licensed under Creative Commons.]
Drug testing with Bayes’ Rule
A new drug for leukemia works 25% of the time in patients 55 and older, and 50% of the time in patients younger than 55. A test group consists of 17 patients 55 and older and 12 patients younger than 55.
(a) A patient is chosen uniformly at random from the test group, the drug is administered, and it is a success. What is the probability the patient was in the older group?
(b) A subgroup of 4 patients are chosen and the drug is administered to each. What is the probability that the drug works in all four patients?
[Author Mark Huber. Licensed under Creative Commons.]
