STATISTICS.... Please HELP... I really do not understand this...... How many different 10 letter words (real or imaginary) can be formed from the following letters? H, Y, H, T, X, X, Y, G, A, X
hint: multinomial coefficient
Unfortunately, I don't know what that means either. It's my 1st time taking stats & it's online.
which numbers repeat and how often do they repeat?
H, Y, H, T, X, X, Y, G, A, X H-2 Y-2 T-1 X-3 G-1 A-1
so the number of arrangements is \[\frac{10!}{2!2!1!3!1!1!}\]
ok, so, that's step 1.
I saw this set up, then I saw n with small k. What does that mean?
? \[_nC_k\]
|dw:1332100875820:dw|
did they give a definition for that?
usually that is for a sequence
\[n_1n_2\cdots n_k\]
Nope. Once I have the above set up (that you have), how do I work that out?
Yes, that right there, that you just posted. What does that mean?
that is a way of counting when you have k groups and in each group i you have \(k_i\) objects. \[n_1n_2\cdots n_k\] is the number of ways you can pick one object from each group
for example if you have 5 shirts, 3 pants and 4 pairs of shoes...the number of outfits you can make is \(5\times3\times4\)
ok
Ok, so for the above problem, H-2 Y-2 T-1 X-3 G-1 A-1 I would do 2x2x1x3x1x1=12 ?
What do I do with the 10! on top
no they have to be factorials ... \[2!\times2!\times1!\times3!\times1!\times1!\] for the denominator
\[2!\times2!\times1!\times3!\times1!\times1!\] \[=2\times2\times1\times6\times1\times1=24\]
\[10!=10\times9\times8\times7\times6\times5\times4\times3\times2\times1=3628800\]
ok. I am using the 10 because there are 10 alphabets. Multiply going in descending order. ok, so my numerator 3628800 and my denominator is 24 No,do divide theses?
yes you need to divide the two numbers
151,200 is my answer
good
Do you have a min, and I can try another one
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