What does SIGMA mean in this equation (what function do I do?)?
476565
As best as I can translate, the equation you are intending looks like this:\n\nΣ [12^4 (.56-.09 √¯(11.8)) (.1+.9*.5)]\n\nIn which case, the problem is incomplete. The summation function, Σ, requires that there be a variable, such as x, in the equation. It also requires that the variable x have set parameters and that these parameters are shown above and below the summation symbol. \n\nFor example:\n\nx=5\n Σ [12^4 (.56-.09x √¯(11.8)) (.1+.9*.5)]\nx=2\n\nYou ignore Σ for the moment, and find the solution of the rest of the expression for each of the values of x indicated (2, 3, 4, & 5). You will then have just four numbers; in other words, all those messy operations will be gone. Σ means you add those numbers now.\n\nIn all cases, the order of operations are as follows:\n\nParentheses, Exponents (√¯ is just an exponent of ½), Multiplication/Division, Addition/Subtraction, Summation\n\nAddition is not Summation and shouldn't be mistaken for it.\n\n\nTo answer your other question, when there is no other operation between numbers, or parentheses, the default operation is multiplication. Therefore, after finding the square root of 11.8, you do indeed multiply that answer with .09.\n\n\nP.S. All the mathematical symbols in this explanation were found using my computer's character map. You can do a search on your computer to find yours. Click advanced. The bottom field allows for searches. (My version of the square root symbol is the square root symbol followed by a macron.)
868541
the truth about this is find the right formula for this equasion, then set it with ur need of what space you put it in to example : =sum(a1:a28)
741999
whats the equation or formula u need help with?
898307
a)\nE(x) = Summation of x*f(x)\n  = 0*(1/15) + 2*(2/15)+........+5*(3/15)\n\nAlso E(x) = mean, which we'll say is u\nSo....u=E(x)\n\nVar (x) = Summation of ((x-u)^2)*f(x)\n = ((0-u)^2)*(1/15) + ((1-u)^2)*(2/15)+......+((5-u)^2)*(3/15)\n\n\nb) E(4x^2-2x+1) = summation (4x^2-2x+1)*f(x)\n = (4(0)^2-2(0)+1)*(1/15) + (4(1)^2-2(1)+1)*(2/15)+....\n....+(4(5)^2-2(5)+1)*(3/15)\n = 1*(1/15) + 3*(2/15)+.....+91*(3/15)\n\nI didn't finish the calculations but you get the idea.\n\n\nFor the sake of notation:\n\nx^2 means "x squared"\nFor this example... F(0) = 1/15, F(1) = 2/15,...., F(5) = 3/15
955889
Alright.\n\nE(S1) = E{(L1/2 + L2/2)^2}\n= Var(L1/2 + L2/2) + E^2(L1/2+L2/2) (Uses the fact that Var(X) = E(X^2) - E^2(X))\n= 0.25(sigma^2) + 0.25(sigma^2) + (L/2 + L/2)^2 (Since L1 and L2 are independent)\n= 0.5(sigma^2) + L^2.\n\nSo the bias of S1 is 0.5(sigma^2)\n\nE(S2) = E{0.5(L1^2 + L2^2)}\n= 0.5E(L1^2) + 0.5E(L2^2)\n= 0.5(Var(L1) + E^2(L1)) + 0.5(Var(L2) + E^2(L2))\n= 0.5(sigma^2) + 0.5L^2 + 0.5(sigma^2) + 0.5L^2\n= sigma^2 + L^2\n\nSo the bias of S2 is sigma^2.\n\nSo that means that S1 has the lower bias.\n\nPerhaps S3 = L1L2 is unbiased?\n\nE(L1L2) = E(L1)E(L2) (Since both are independent)\n= L*L\n= L^2\n\nBias is zero.  There you go!
175190
It is a function that tells the sign of a number. It is written as:\ny = sgn x\n\nIf x is a positive number, then sgn x is 1\nIf x is a negative number, then sgn x is -1\nIf x is 0, then sgn x is 0\n\nIt is called signum function, not sign function, to avoid misinterpretation/confusion with the sine function(A circular function) which is very different.\n\nGood Luck ;-)
151654
It's multiplication.\n\n(64500)(0.02) = 1290\n\nScientific notation is 1.29 * 10^3
991696
To define an equation, you can use the syntax\nf := x -> (k*x*(1-x));\nWhich is creating a function defined on a variable x.\nThen, you can set the value of k by saying \nk := 2;\nIf you then say\nf(.1);\nit will give you the value of f(.1).  You can repeat this with the value you get from this.
1001878
The formula for Standard Deviation:\n\nSigma = sqrt(E((X-E(X))^2) = sqrt(E(X^2) - (E(X))^2)
854317
I think you're slightly confused. ∑ is sigma, and refers to summation. The integration symbol ∫ is called the "long s." And what it refers to is integration. Although the simplest method of evaluating an integral is usually antidifferentiation (especially when exact solutions are desired), this is not the only method, and there are many functions which are integrable, but whose antiderivative cannot be written in terms of elementary functions. e^(x²) is one such function. In these cases, other methods, such as numerical integration or taylor series expansion, must be used to evaluate the integral.\n\nAlso, as mentioned by the previous poster, if the ∫ symbol appears without limits it refers to the antiderivative in general (which can still be defined using the integral, even if it cannot be expressed in terms of elementary functions).
149503
Right, so feed the numbers into your calculator and press the SD button.\n\nOr enter it into Excel and use teh standard deviation function.
354577
The function f(x)=Sigma of((f^n)(c)/n!)*((x-c)^n) is what you start with.  You can replace the Sigma(sum) with an integral.  Derivatives are the basically the opposite of Integrals.  If you derive the integral, you end up back at the start: ((f^n)(c)/n!)*((x-c)^n).  It might be easier to use a graph to see what happens. \n\nBut basically, intervals are merely used to look at a part of whatever is on the graph.  It doesn't matter what you do to that part, you are still looking at that part.  That's why the intervals don't change.\n\nDoes that help you or confuse you?
963851
The question doesn't make sense: what is T(n/4) supposed to mean when n = 2 or 3 or 5 ...??
1109888
Jennifer, I'm a little bit puzzled about your question because you're asking for what the funtion is and you have it written there.  The funtion is s = -16t2 + v0t + s0\n     What I really think you want is the solution.  Correct?  Well, here's how you get that.  You put in 0 for s0, and 64 for v0.  ALSO, s, on the left side of the equation, is also zero because it will land back on the ground when it's done.  When you solve using these numbers, the only variable left is t.  And when you do the algebra, \n  0  = -16t2  +  64t  + 0\n \n16t2  =  64t\n\n16t  =  64\n\nt  = 4      seconds, that is.\n\nI hope this works.  I'm a physics teacher.  If you need further clarification for this problem, or if you need help with any others, feel free to write me at fortitudinousskeptic@yahoo.com\nI'll be glad to help!
1156519
If you are using a sample set of data you can press stat/edit - then press enter/enter a list of numbers/ press stat again/move the arrow to calc/ select 1-Var stats/ press enter/press 2nd and then 1 (or L1)/ press enter.\n\nx bar = the sample mean\nSx = the sample standard deviation\nVariance = Sx squared
846377
Mean (m) = 20.142857= 20.14\n\nMedian = 4th no. = 21\n\nxffx(x – m)(x-m)2\n12112-8.1478.4996\n17117-3.149.8596\n19119-1.141.2996\n211210.860.7396\n221221.863.4596\n241243.8614.8996\n261265.8634.3396\n71410.02143.0972\n  2                2\nS   =  (x  - x)   / f   = 143.0972 /7 = 20.44171\n        \n S (SD) = &#92;/ 20.44171 = 4.521251 = 4,52 Approx.
115539
Check out wikipedia.org for info on sigma notation.