- #1
619snake
- 29
- 0
Homework Statement
the weight of items produced by a production line is normally distributed with a mean of 12 ounces and a standard deviation of 2 ounces.
Suppose that quality control requires the weight of items to be within 8 and 16 ounces. You select 7 items at random (each item is independent). What is the probability that 3 items will fulfill quality control requirements.
What I have to the moment is:
X~n(12,2)
P(x<16) - P(x<8)
z=(16-12)/2
z=2
z= (8-12)/2
z=-2
p(z<2)-P(z<-2)
=.9772-.0228
=.9544
p(x>20)
z=(20-12)/2
z=4
P(z>4) = 1
Those where other requirements of the problem. I'm stuck at the supposing, can't decide if it is binomial or not, and how to start the procedure