There is a 0.63 probability that Mobil stock will rise, a 0.75 probability Gulf stock will rise and a 0.4 chance that both stocks will rise. Find the probability that neither stock will rise. There is a 0.63 probability that Mobil stock will rise, a 0.75 probability Gulf stock will rise and a 0.4 chance that both stocks will rise. Find the probability that neither stock will rise. @Mathematics

- anonymous

- jamiebookeater

I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!

At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga.
Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus.
Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.

Get this expert

answer on brainly

SEE EXPERT ANSWER

Get your **free** account and access **expert** answers to this

and **thousands** of other questions

- anonymous

So .37*.25=.0925
But the answer key for a similar problem( only difference is .47 instead of .4), the answer is .2775. The answers shouldnt differ that much right?

- Zarkon

why are you multiplying those two numbers?

- anonymous

isnt that how you get the probability for AND?

Looking for something else?

Not the answer you are looking for? Search for more explanations.

## More answers

- Zarkon

not in this case

- anonymous

Then Im completely lost.

- Zarkon

your events are NOT independent

- anonymous

I think that's the concept that I dont quite understand

- anonymous

would the formula be P(A U B)/P(A)?

- Zarkon

no

- Zarkon

use \[P(A^c\cap B^c)=1-P(A\cup B)\]

- anonymous

so the 1-P(none) formula

- Zarkon

for any event E
\[P(E)=1-P(E^c)\]
or \[P(E^c)=1-P(E)\]

- anonymous

so how exactly does not being independent effect the problem?

- Zarkon

events A and B are independent iff
\[P(A\cap B)=P(A)P(B)\]

- Zarkon

you cant use this formula since A and B are not independent

- anonymous

So in terms of a venn diagram, independent is two circles that dont intersect. and not independent has two circles that do intersect.
and in this problem the intersection is .4?
So I need to find the sum of each part of the venn diagram, subtract from one (to get the number outside the diagram) which would be the "neither". Correct?

- Zarkon

NO

- Zarkon

independent events intersect (most of the time)

- Zarkon

if A and B are independent and P(A)>0 and P(B)>0 then A and B have to intersect.

- Zarkon

use
\[P(A^c\cap B^c)=1-P(A\cup B)=1-[P(A)+P(B)-P(A\cap B)]\]

- anonymous

|dw:1321204843404:dw|
Is what Im picturing
Basically, I was doing P(Acâˆ©Bc)=1âˆ’P(AâˆªB)=1âˆ’[P(A)+P(B)âˆ’P(Aâˆ©B)] except that mine adds instead of subtracts the intersection.

- anonymous

so to get neither dont you need to get rid of all that is in the circles? including the intersection?

- Zarkon

yes

- anonymous

wouldnt that be adding the intersection?
so
1âˆ’[P(A)+P(B)+P(Aâˆ©B)] instead of
1âˆ’[P(A)+P(B)âˆ’P(Aâˆ©B)]

- anonymous

oh wait

- anonymous

I see nevermind

- anonymous

|dw:1321205205257:dw|
So the answer is .02? that's seems really small.(compared to the other answer)

- Zarkon

it is .02

- anonymous

ok thanks

- Zarkon

I would check your key again...if you just change from .4 to .47 then .2775 is not the answer

Looking for something else?

Not the answer you are looking for? Search for more explanations.