00:01
Hi guys, from the information we can observe that combination problems in semiconductor manufacturing can result a functional defect, a minor defect, or not affect in the final product.
00:13
So suppose there are 20%, 50 % and 30 % of the combination problems results in the functional minor and not effects respective.
00:25
So here we have 24 functional, okay.
00:31
20%, so this is percent, then 50 % for the minor, and 30 % for no defects.
00:46
Okay, so assume that the defects of 10 contamination problems are independent, so let x be the random variable that represents the number of contamination problems that result in the functional, okay, and y, be the random variable that represents the number of contamination problems that results in the minor, and z by the same way for no effects.
01:17
Okay, so the random variables x, y, and z have a multinomial distribution with parameters n equal 10 p1 equal 0 .2 p2 equal 0 .5 and p3 equals 0 .3.
01:39
So the joint probability mass function we can calculate it such as probability of x equals x, y equals y and z equals z so it's n factorial over x factorial y factorial x factorial x x x x x x times p1 power x times p2 power y times p2 power y times p 3 power z okay so this is 10 factorial over x factorial y factorial z fictorian x 0 .2 power x times 0 .5 power y times 0 .3 power z okay so now calculate the probability that the 10 contamination of problems in part a we need to calculate the 10 contamination problems results in two functional defects and five minor defects okay so here we have to calculate the probability of x equals to y equals 5 and z equals 3 so it's 10 factorial over 2 factorial 5 factorial 3 factorial times 0 .2 our 2 times 0 .5 5 times 0 .3 per 3.
03:12
So it's 0 .085...