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WHO LIKES MATH? (Help needed, please) (pg. 4)
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| DJ_Science |
| I had a great idea for my Kipling prank for the year I graduated. I really wanted to get all of the engineers together, have them build catapults and lay siege to TSH. But everyone thought it would be too much work for their last year. |
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| Aitizaz |
seems quite interesting and intense! good luck!
Irish: good luck to your mom on the MBA...feel free to post any more stats related problems...hehe
i bid you two goodnight. |
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| Irishaddict |
| quote: | Originally posted by DJ_Science
I had a great idea for my Kipling prank for the year I graduated. I really wanted to get all of the engineers together, have them build catapults and lay siege to TSH. But everyone thought it would be too much work for their last year. |
HAAAAAAAHAHAHAHA TSH is such a hole. I'll help. :)
On a sidenote however, the overhaul they did on Hamilton Hall is pretty impressive. |
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| Irishaddict |
| quote: | Originally posted by Aitizaz
i bid you two goodnight. |
Night! |
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| DJ_Science |
Aitizaz: Good night man!
Irish, I've not been back to campus in about two years so if it was a recent chance I have to take your word for it. But, for now I am going to follow Aitizaz's lead and head to bed. Are you on MSN? |
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| Euphorica |
engineers are douche bags :eyespop:
PVD in T.O... i wish |
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| bluE_Neon |
| quote: | Originally posted by DJ_Science
I hope this makes sense...
> 1. A normal distribution has a mean of 80 and a standard deviation
> of 14. Determine the value above which 80 percent of the values will > occur.
You need a table for this one. Its about 68.3. Basically you want to look at z&sigma for which a one tailed test gives 20 percent outside. They key to this is a one tailed test. then &mu - z&sigma is the value above which 80% will fall.
> 2. Assume a binomial probability distribution with n=40 and p=.55.
> Compute the following:
> a) the mean and standard deviation of the random variable.
mean = &mu = n*pi
&sigma^2 = n*p*q = n*p*(1-p)
> b) the probability that x is 25 or greater.
You have to add a bunch of terms
P(x >= 25) = sum{n=25 to 40} {40!/[(n!)(15!)]}(0.55)^n(0.45)^(40-n)
= 0.2142
> c) the probability that x is 15 or less.
See "b", just sum from 0 to 15, P(x <= 15) = 0.0196
> d) the probability that x is between 15 and 25 inclusive.
P(15 <= x <= 25) = 0.8588 Again, same as above, just sum from 15 to 25.
> 3. Two-litre plastic bottles used for bottling cola are shipped in
> lots of 100. Suppose the lots are 5 percent defective. Some bottles > leak, some are too small, and so forth.
> a) In the sample of 100, how many of the bottles contains 8 or more > defectives?
They have essentially told you the mean is 5 or the probability of
the bottle being bad is 5% (mu = N*P, N = 100 => P = 0.05%).
You can use the diff. of the binomial from here on with P = 0.05.
(There i am defining a pass as a broken bottle).
P(8 or more) = 1 - P(7 or less)
= 1 - sum(n=0,7) [(100!/(n!*(100-n)!)](0.05)^0.05(0.95)^0.95
= 0.2340
> b) Tell why this situation meets the binomial assumptions.
Its a pass/fail test. Either the bottle has a defect or not. In
these cases, you want a distribution that is binary in nature, ie
the binomial.
> c) What is the probability that a shipment of plastic bottles
> contains 8 or more defectives?
Isn't this the same as a?
> d) What is the probability that 8 and 10 bottles are defectives?
at the Prob for 8 and 10 only, P = 0.08158677208886
> e) What is the probability that there are exactly 8 defectives?
0.10602553736479 same as above, but only the n = 8 term counts
> f) What is the probability that there are no defectives?
0.00592052922033 n = 0 term only |
Buddy!!! You just made me miss finite & business math. Awesome job :) |
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| StereoPrincess |
we should make an pffical "help with school problems" thread.
and steve can answer them all. |
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| El Kay Dee |
| quote: | Originally posted by StereoPrincess
we should make an pffical "help with school problems" thread.
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pfficial as in pwned? |
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| DJ_Science |
| quote: | Originally posted by StereoPrincess
we should make an pffical "help with school problems" thread.
and steve can answer them all. |
Maybe just the math/physics ones :).
| quote: | Originally posted by bluE_Neon
Buddy!!! You just made me miss finite & business math. Awesome job :) |
Is that a good thing? I can't tell?! :( |
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| bluE_Neon |
| quote: | Originally posted by DJ_Science
Is that a good thing? I can't tell?! :( |
LOL, yea buddy! I love math and I do miss the thought :) |
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