What does the coefficient of variation exactly indicate?
147662
The coefficient of variation just compares the standard deviation to the mean.  It is calculated S.D./ Mean sometimes * 100.  It is difficult to compare standard deviations of variables where the units are not the same.  For example if one variable had units in million of dollars and another in cents how do you compare their variability?  One way to compare them and get an idea of their variability is to use the C.V.
1161445
The equation for direct variation is y = kx.\nk is the constant of variation.\n\n#1.  -10 = k(2)    Solve for k\n           -5 = k\nSo, the equation for direct variation is y = -5x -- just substitute the k back into the equation.\n\n#2.  7 = k(3)   Solve for k\n       7/3 = k\n     y = (7/3)x
856604
Coefficient means the number in front of a variable.  In the equation\n\ny = 5x - 3, 5 is the coefficient of x, and therefore is the slope.\n\ny = x + 4 the coefficient of x is 1\n\ny = 3x/4 + 11 the coefficient of x is 3/4\n\netc\n\nJust be sure y is by itself at the beginning of the equation\n\nexample if you have 4x + 5y = 20, you must subtract 4x from both sides then divide by 5 to get\n\ny = -4x/5 + 4   coefficient of x is -4/5
101856
Standard deviation is a measure of the variability in a sample.  A small standard deviation means that most observations are clost to the mean (average).  The standard deviation is the square root of the variance.  The variance is calculated by taking the difference between each observation and the mean, squaring it, summing for all observations, then dividing by the number of observations less one.\n\nwith m = mean and X1 ... Xn being the observations:\n\nvariance: V = [(X1-m)^2 + (X2-m)^2 ... + (Xn-m)^2] / (n-1)\nstandard deviation: sigma = sqrt(V)
806650
Direct variation when applied to two variables x and y is usually expressed in the form:\n\ny= k*x   where is k is the constant of variation\n\nSo y/x = k\n\nFrom your first values for x and y, you can determine k:\n\n-4.8/-1.6 = k = 3\n\nNote: x = y/k, so from your 2nd value for y, and from k = 3, you can determine the 2nd value for x:\n\nx = -24/3 = -8\n\nAs far as slopes go, you know that the standard form for the equation of a line is:\n\ny = mx+b  where m is the slope and b is the y intercept (i.e. when x = 0)\n\nYou can see that your example of direct variation is equivalent to a line having slope k, and passing through the origin (0,0) so b=0.\n\nDirect variation is the same as direct proportonality:\n\nhttp://mathworld.wolfram.com/DirectlyProportional.html
1109806
correlation coefficient i really couldnt tell you a formula, but there is a button on your graphing calculator that tells you it, correlation coefficient is a number from 0 to 1, stating how close a best fit line is to a series of points, 1 being perfectly on the line, so unless your dealing with a best fit line i have no idea...
268119
To answer that question you would have to know if the differences between "having a variation" and "not having the variation" are normally distributed.  If so, you could make an assumption on the number to look at based on normal distribution and 3 standard deviations.\n\nIf there is no normal distribution to the data, then you would have to determine your own "statistics" for the odds that the deviation would occur, and calculate the number based on the possible number of "variations" that could occur, versus the odds that any one could occur.
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c.\n\nIn probability theory and statistics, the coefficient of variation (CV) is a measure of dispersion of a probability distribution. It is defined as the ratio of the standard deviation to the mean
432008
t=rho/(sqr((1-rho^2)/(n-2)))\nwhere:\n\nrho: correlation coefficient\nn: number of observations
858220
Depends on what variable you're differentiating with respect to:\ndV/dr : 2/3*pi*r*h\ndV/dh:  1/3*pi*r^2
307198
It is linear on intervals, on (- infinite, 0) and on (0, +infinite) but not on the whole R. \n\nTry plotting it, you get a reversed V, not a straight line.
266011
the variation from scan plane to scan plane is normally larger than the variation over angle for a single scan plane
203030
its a representation of the actual numbers-----
1135408
OH NOES THIS IS LIKE A MATH PROBLEM!!!! i can't handle any more variables :( sry.\n\n\nhahahaha.
302694
A statistic used as a measure of the dispersion or variation in a distribution. It is equal to the square root of the arithmetic mean of the squares of the deviations from the arithmetic mean. Simply put, standard deviation measures how spread out the values in a data set are. More precisely, it is a measure of the average difference between the values of the data in the set. If the data points are all similar, then the standard deviation will be low (closer to zero). If the data points are highly variable, then the standard variation is high (further from zero). the greater the standard deviation, the higher the risk. it is always positive, and NEVER negative. the formula you use is....well i can't write it because i don't have the symbols on my keyboard, but i'll try:\n\n\nσ= √(Σ[D-E]^2P)\n\nwhere:\nσ=sigma=standard deviation\nΣ=capital sigma= the sum of\nD=outcome\nE=expected value\n^2= squared\nP= Probability\n√=square root\n\nhere is an example:\n\n(Assumptions)(Outcome probability)(Outcomes)\n(Pessimistic)(0.2)                     (300)\n(Successful)(0.6)                     (600)\n(Optimistic)(0.2)                     (900)\n\n(sorry, the table won't keep the spaces, so i put brackets in)\n\nok, you need the expected value, which is the sum of all of the outcomes, times their probabilities, like so:\nexpected value = 300×0.2+600×0.6+900×0.2 = 600\n\n\nthen standard deviation would be calculated like so:\nstandard deviation = {(300-600)2×0.2+(600-600)2×0.6+(900-600)2×0.2}½ = 190\n\nhope that helped! oh, and if you don't understand, the "to the power of 1/2" part is the same as taking the square root.
1110391
It is based on mean and standard deviations (statistical stuff). With just the information you gave, it is impossible to tell.\nWe would need to know the mean, standard devaition, and method of calculating scale...but then again if we had all this stuuf you would be able to asnwer your own question, right?
258090
often it refers to the controllable factors. It could mean that other possible influences on the research have been accounted for.