Answer:
0.4546
Step-by-step explanation:
nCr = n!/(n-r)!r!
Number of ways of selecting the four defective voltage regulators from 12 = 12C4 = 12!/(12-4)!4! = 12!/8!4! = (12 *11*10*9)/(4*3*2*1)
12C4 = 495 ways
Number of ways of selecting 2 defectives from line 1 = 6C2 * 6C2
6C2 = 6!/(6-2)!2! = 6!/4!2! = (6*5)/(2*1) = 15
6C2 * 6C2 = 15*15 = 225 ways
Probability = Number of possible outcomes/ Number of total outcomes
Probability that exactly 2 of the defective regulators came from line 1 = 225/40.95 = 0.4546
Answer:
Step-by-step explanation:
For this case we can define the random variable of interest as: "The nicotine content in a single cigarette " and for this case we know the following parameters:

And for this case we select a sample size of n =100 and we want to find the following probability:

And for this case we can use the z score formula given by:

And replacing we got:

And we can find the required probability with the normal standard table and we got:

Well this depends on the the the size of the cover
Answer:
100
Step-by-step explanation:
160 * (5/8) = 100
See, pls, the offered decision:
1. this ratio has another form: 2x/3x/4x;
2. the difference between the largest and the smallest is 4x-2x=10.
Then x=5, and the sequence of numbers is 10/15/20, where 15 is the middle number.
Answer: 15.