Math/ genetics Q
Started by prsndwg
The probability is 1/2 x 1/2 x 1/2 =1/8
Now to arrange the 3, you can have H, T, T
T, H, T
T, T, H
so the probability is 3/8
The probability of one of these events independantly is 1/2. You then use the product rule which is multiply the probabilities of each individual event by each other.
(1/2)(1/2)(1/2) = 1/8
1/8 is the chance (individual probability) for one outcome of this coin flipping (HHH, HTH, TTH, etc.)
The probability of coints being flipped in any one of these 8 orders = the sum of individual probabilities.
1/8 + 1/8 + 1/8 = 3/8
The probabiliy of this happening is 3/8.
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So, I know on the practice tests there are measurements/unit conversions such as fl.oz.to gal., etc. Anyone know a website these unit measurement conversions?
Thanks.
Thanks.
Just type it in to google search.
Search: "oz to gallon" and it gives you the conversion
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4GGLL_enUS321US321&q=oz+to+gallon
You can do that with anything. Or even type in like 63.72 oz to gallon and it will convert that too.
FML. I'll try to figure this one out.
The key has to be wrong.
Possibilities:
HHH
HHT
HTH
THH
HTT
THT
TTH
TTT
8 possibilities. There are three possibilities which include two heads and one tail. The probability of getting two heads and one tail is 3/8.
Are you sure you stated the question correctly?
Avery your answer is correct... 3/8👍👍
I was going crazy sorting through my genetics notes and coming up with the same answer. 😕
Thanks for the reassurance there!
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What book is this?
and to the OP... since when is probability and statistics consider genetics?...
I'm not the OP but... Inheritance problems sir.
Taken from my genetics notes:
why there is a 1/4 on the 3rd order?
The 1/4 could just as well been on the 2nd order as the 3rd order. This is just one of the X possibilities for an order including 3 normal & 1 PKU offspring.
And the picture above didn't come from my notes. I don't think gamete frequencies were part of this problem so I'm assuming this problem requires hardy-weinberg equilibrium? Otherwise with those gamete frequencies, 1/4 of the population would not be PKU.
You never said what the probability of having PKU actually is. Is it a 1/4 chance? Just because you are looking for 1/4 of the children to have it doesn't mean that 1/4 is the probability.I'm not the OP but... Inheritance problems sir.
Taken from my genetics notes:
Going by the standard Punnett square perhaps it is, but you would want to make a note of that. If there were 5 children then you'd have a better example.
prsndwg: The probability of being normal is 3/4 (apparently, see note above). The probability of having PKU is 1/4. So in 4 children, the probability of ANY one and ONLY one of them having the disease is (3/4)(3/4)(3/4)(1/4). Avery07 just put the 1/4 in the third position.
Edit: Okay you put up a Punnett square with different probabilities. You have to use those and not 3/4, 1/4.
3/4 of the offspring will be normal (A/-)
1/4 of the offspring will be affected (a/a)
got it thanks
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The equation for an "exactly x out of y times" question is something like
nCr p^i q^(n-r)
where p is your favored outcome, q is your unfavored outcome, r is your favored frequency. nCr represents the number of such combinations allowed
For a 3-pick-2 question, it will be
3C2 (.5^2)(.5^1)
or
3(1/2)(1/2)(1/2)
In another example: You throw a die 10 times. what is the probability that it will land on "3" exactly 2 times?
The probability of a 3 landing is 1/6, and the probability of not landing is 5/6. The probability then is: 10C2 (1/6)^2 (5/6)^8
nCr p^i q^(n-r)
where p is your favored outcome, q is your unfavored outcome, r is your favored frequency. nCr represents the number of such combinations allowed
For a 3-pick-2 question, it will be
3C2 (.5^2)(.5^1)
or
3(1/2)(1/2)(1/2)
In another example: You throw a die 10 times. what is the probability that it will land on "3" exactly 2 times?
The probability of a 3 landing is 1/6, and the probability of not landing is 5/6. The probability then is: 10C2 (1/6)^2 (5/6)^8
