Probability problem for statisticians/mathematicians

[expat]

you guys are missing one factor

0.45 is the correct answer, but each visit to the ISS consists of TWO trips, one there and one back.

hence the doubling of the chances of a failure

2 trips but 1 sortie. Depends what they meant.

[ASB]

And so far, they've managed to lose one going & one coming back...

I wonder which one hurt the most...

And an odd number of missions. I was worried for a minute, I though there might be one stuck up there.

[EternalOptimist]

2 trips but 1 sortie. Depends what they meant.

The yanks dont understand sorties, not like us battle of Britain Vets. Why one training mission over Minnesota counted as sixteen sorties and they got a purple heart as well if they shat their pants

[expat]

The yanks dont understand sorties, not like us battle of Britain Vets. Why one training mission over Minnesota counted as sixteen sorties and they got a purple heart as well if they shat their pants

Reminds me of their Grenada invasion in the early 80s: 8000 campaign medals, only 5000 actually went to Grenada.

Not all of those set foot on Grenada, some were air force whose job was to bomb hospitals, shoot up their own side, etc.

[EternalOptimist]

Reminds me of their Grenada invasion in the early 80s: 8000 campaign medals, only 5000 actually went to Grenada.

Not all of those set foot on Grenada, some were air force whose job was to bomb hospitals, shoot up their own side, etc.

you got to larf

[Marina]

And so far, they've managed to lose one going & one coming back...

I wonder which one hurt the most...

Probably the one going up (Challenger disaster), because despite a 20g jolt caused by the explosion, apparently they were still likely alive and conscious for a few seconds afterwards as the crew cabin they were in fell away.

I'd guess the Columbia crew (Columbia disaster) only had a second or so to realize something was wrong, before their shuttle broke up at a speed of Mach 19 which must have killed them instantly. According to that link, their final words at 8:59:32 were "Roger, uh, bu - [cut off in mid-word] ..."

[Spartacus]

Good old DOS.

On May 9, 2008 it was reported that data from a disk drive on board Columbia survived the shuttle accident.[19] The drive was used to store data from an experiment on the properties of shear thinning.[20] Although part of the 340MB drive was damaged, the area that contained the data was unharmed. Because the computer using the drive on board Columbia was running a DOS filesystem, all of the data had been written to the drive in sequence; whereas a modern-day operating system may have scattered the information around the drive for performance reasons.

[DaveB]

Is there a secondary market in these ‘ Xeno geek points’? if so, how do I price them?

They are like carbon credits. You need to find someone with a low geek footprint to trade them with.

[scooterscot]

According to the question a successful mission is equal to a completed space station. Assuming the same space shuttle is used a total of 59 flights are required for a completed station. So the question is a little cryptic.

30 flights would only see the station partially built.

Poisson distribution would not be used, as some have suggested, as the Poisson is used to look as a discrete window of time, a minute an hour a year etc...

Indeed the Binomial distribution is correct and would only consider, fail / non-failure, on / off, yes / no. (The Pr of failure and Non-failure are two events that cannot occur at the same time, stat guys call this Mutually Exclusive)


The Pr of failure in one flight is = 1 - 0.98

The Pr of failure in 30 continuous flights is = 1 - ( 0.98 ^ 30) which is 0.454515681





Figures don’t lie, but liars can figure

[Board Game Geek]

Well, I have calculated with complete certainty that if none of the shuttles fly to the ISS, and remain on terra firma, the chance of them blowing up mid-mission is reduced to 0%.

You can't be too careful you know