LOS 8c, Probability

[MisterL]

Hi there,
the LOS states that a probability of occurrence of 0.125 equals 1/7 (the odds for the event occurring are one-to-seven). But some lines below its stated that "odds for an event are one to six, we can compute the prbability of occurrence as 1/7".
This doesn't make sense to me...

Any ideas?

Thanks

 

[mcpass]

I've understood it to be what you first state. 0.125 equals 1/7 or one to seven.

 

[mwvt9]

Probability and odds are different. If you do the math it works...but it is not intuitive.

(1/8)/(7/8)= .142857 or 1/7

The numerator is the PROB of the event happening and the denominator is the PROB of the event not happening.

Because you know that the numerator is happening one out of eight times, the denominator must happen seven out of eight times (assuming mutually exclusive and exhaustive events). So to figure out the odds for divide the probability for by the probabiltiy against.

You can also figure out the odds against by flipping the equation I think

(7/8)/(1/8)=7 or 7/1

 

[MisterL]

Hm, thanks for the replies but it still doesn't make much sense to me...

 

[Super I]

Look at what you wrote above:

One TO six is not the same as one IN six.

The first expresses the number of favorable outcomes compared to the number of unfavorable outcomes, the second expresses the number of favorable outcomes compared to the number of total possible outcomes

That's the difference in how these things can be expressed.