Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
A factory manufactures screws, machines X, Y and Z manufacture
respectively 1000,2000, 3000 of the screws,1%, 1.5% and 2 % of their
outputs are respectively defective .A screw is drawn at random from the
product and is found to be defective. What is the probability that it is
manufactured by the machine X ?
 one year ago
 one year ago
A factory manufactures screws, machines X, Y and Z manufacture respectively 1000,2000, 3000 of the screws,1%, 1.5% and 2 % of their outputs are respectively defective .A screw is drawn at random from the product and is found to be defective. What is the probability that it is manufactured by the machine X ?
 one year ago
 one year ago

This Question is Closed

whpalmer4Best ResponseYou've already chosen the best response.1
Figure out how many defective screws are made by each machine. The probability that a defective screw is made by machine x is just the ratio of the number of defective screws made by machine x to the total number of defective screws.
 one year ago

shubhamsrgBest ResponseYou've already chosen the best response.1
there are total 1000 + 2000 +3000 screws = 6000 we chose a screw,P(it comes from X) = 1000/6000 = 1/6 P(it comes from B) = 1/3 P( " " " C) = 1/2 Now we know it is defective P(defective from X) = 1% = 0.01 P(defective from Y) = 0.015 P( " " Z) = 0.02 Our favorable outcome is P(selecting from X)*P(defective from X) total probability = P(selecting from X)*P(defective from X) + P(selecting from Y)*P(defective from Y) + P(selecting from Z)*P(defective from Z) so required probability = fav probab/total probab just substitute values. NOTE  I used Baye's theorem.
 one year ago

whpalmer4Best ResponseYou've already chosen the best response.1
That's a complicated way of arriving at the same result :) No need to know the percentages of selecting from each machine — you just need to know how many defective screws were made by each machine. Nondefective screws are irrelevant in this problem.
 one year ago

whpalmer4Best ResponseYou've already chosen the best response.1
If we were trying to find the problem that a randomly selected screw would turn out to be a defective screw made by machine X, the extra work would be useful.
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.