# Ahh, simple probability problem I can't get

#### Syringer

##### Lifer
Jilll's average bowling score is 170 with standard deviation of 20, Jack is 160 and 15.

What's the prob that Jack's score is higher?

#### Iron Woode

##### Elite Member
Super Moderator
why are there 3 L's in Jill's name?

15/spider

#### mitaiwan82

##### Platinum Member
Originally posted by: Iron Woode
why are there 3 L's in Jill's name?

BYOBB

Super Moderator

#### Syringer

##### Lifer
Lisa: Come to Homer's BBBQ, the extra 'B' is for BYOBB.
Bart: What's that extra B for?
Homer: That's a typo.

#### Syringer

##### Lifer
Now back to statS!

#### HomeBrewerDude

##### Lifer
2 sample t test or something like that

#### beer

##### Lifer
Are we assuming normal gaussians here?

convert them into standard gassians and use the CDF table for the random variables of their scores

#### TuxDave

##### Lifer
Originally posted by: Syringer
Jilll's average bowling score is 170 with standard deviation of 20, Jack is 160 and 15.

What's the prob that Jack's score is higher?

Find the probability that Jack-Jill is greater than 0. You subtract the means, you add the variance, and then use a Z-table.

#### Yo Ma Ma

##### Lifer
Originally posted by: Iron Woode
why are there 3 L's in Jill's name?

That's what makes it such a tricky question. Those wacky profs.

depends on jacks efforts in the attempt to get laid that night

if he's goin for nook, he's gonna let her win

#### KnickNut3

##### Platinum Member
Originally posted by: TuxDave
Originally posted by: Syringer
Jilll's average bowling score is 170 with standard deviation of 20, Jack is 160 and 15.

What's the prob that Jack's score is higher?

Find the probability that Jack-Jill is greater than 0. You subtract the means, you add the variance, and then use a Z-table.

:thumbsup:

#### iamme

##### Lifer
wtf are they doing bowling??? there are pails of water to be fetched!! :|

#### Iron Woode

##### Elite Member
Super Moderator
Originally posted by: troytime
depends on jacks efforts in the attempt to get laid that night

if he's goin for nook, he's gonna let her win
Jack and Jill
went up the hill.
each with a buck and a quarter.
Jill came down with \$2.50.......

#### Syringer

##### Lifer
Originally posted by: TuxDave
Originally posted by: Syringer
Jilll's average bowling score is 170 with standard deviation of 20, Jack is 160 and 15.

What's the prob that Jack's score is higher?

Find the probability that Jack-Jill is greater than 0. You subtract the means, you add the variance, and then use a Z-table.

You're a geeeeeeeeniusss!

#### KnickNut3

##### Platinum Member
Originally posted by: troytime
depends on jacks efforts in the attempt to get laid that night

if he's goin for nook, he's gonna let her win

Definitely. His score is NOT a random variable--it is inversely proportional to her hotness.

#### beer

##### Lifer
Originally posted by: KnickNut3
Originally posted by: troytime
depends on jacks efforts in the attempt to get laid that night

if he's goin for nook, he's gonna let her win

Definitely. His score is NOT a random variable--it is inversely proportional to her hotness.

That sounds like a conditional RV to me.
Solve for the joint PDF! They're obviously not indepedent, so you're stuck trying to solve for the marginal then...

Originally posted by: beer
Originally posted by: KnickNut3
Originally posted by: troytime
depends on jacks efforts in the attempt to get laid that night

if he's goin for nook, he's gonna let her win

Definitely. His score is NOT a random variable--it is inversely proportional to her hotness.

That sounds like a conditional RV to me.
Solve for the joint PDF! They're obviously not indepedent, so you're stuck trying to solve for the marginal then...

but if you bring a joint into the picture, jack being high may alter the array of methods used in getting the nook

#### aplefka

##### Lifer
Originally posted by: troytime
depends on jacks efforts in the attempt to get laid that night

if he's goin for nook, he's gonna let her win

:thumbsup: