My Math Forum Find the mean, variance, and standard deviation

 August 27th, 2009, 01:10 AM #1 Newbie   Joined: Aug 2009 Posts: 1 Thanks: 0 Find the mean, variance, and standard deviation Q.7 In an assembly line production of industrial robots, gearbox assemblies can be installed in two minute each if holes have been properly drilled in the boxes and in nice minutes if the holes must be be redrilled. Twenty gearboxes are in stock, 2 with improperly drilled holes. Five gearboxes must be selected from the 20 that are available for installation in the next five robots. i) Find the probability that all 5 gearbox will fit properly. (2 marks) ii) Find the mean, variance, and standard deviation of the time to install these 5 gearbox I have no problem with Question 7(i), but i dont know how to solve 7(ii), the following is my solution but somehow it seems to be incorrect, someone please help me.

 Tags deviation, find, standard, variance

,

,

,

,

,

,

,

# in an assembly-line production of industrial robot, gearbox assemblies can be installed in one minute each if holes have been properly drilled. find the probability that all 5 gearboxes will fit properly

Click on a term to search for related topics.
 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Kinroh Advanced Statistics 1 September 5th, 2013 12:31 PM HenryMolaison Algebra 2 February 20th, 2013 12:33 PM margybear Algebra 3 February 22nd, 2012 09:10 PM tsl182forever8 Algebra 2 February 10th, 2012 05:37 AM jd254 Algebra 0 May 7th, 2009 12:46 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top