Homework Statement
10% of engines manufactured on an assembly line are defective. If engines are randomly selected one at a time and tested, what is the probability that the first defective engine will be found between the 5th trial and the 25th trial, inclusive?
Homework Equations...
Homework Statement
Find the derivative of (1+e^-x)^-1
Homework Equations
The Attempt at a Solution
I can't seem to get anywhere with this. Should I be looking for a property of something like the cosh function to apply to this?
Thanks
So what you're saying is that I have to show that A is a subset of AUB. This is done by definition that AUB=A+B therefore A is a subset of AUB and it follows (as you said) that P(A) is less than or equal to P(AUB). Correct? What would I do to prove the intersection is less than A?
cheers
Homework Statement
Prove the following:
P(A∩B) ≤ P(A) ≤ P(AUB)
Homework Equations
The Attempt at a Solution
I first attempt to show that P(A) is a subset of P(AUB) which therefore means it is ≤ P(AUB):
P(AUB)=P(A)+P(B)-P(A∩B), thus P(A) is a subset of P(AUB)...I think that...