deviation Definition and 388 Threads

I have a question about standard deviation. If I have a hundred of distance data, how can I use standard deviation to choose a suitble range of the distance. What is the relation between standard deviation graph and my data. I can plot a graph using mean and std of the data, but do not know how...

Exam is in the next 30 mins so please reply ASAP. I just need help with this question. For a sample of size 5, x1 - mean = -5, x2 - mean = 9, x3 - mean = -7, x4 - mean = -2 and x5 - mean = 5 What is standard deviation... answer is 6.782 by squaring all the answers, dividing by n-1 and...

Light of wavelength 700 nm is incident on the face of a fused quartz prism at an angle of 77.0° (with respect to the normal to the surface). The apex angle of the prism is 60.0°. n=1.459. a) the angle of refraction at the first surface (b) the angle of incidence at the second surface (c)...

Homework Statement This is my data: 42.4, 65.7, 29.8, 58.7, 52.1, 55.8, 57.0, 68.7, 67.3, 67.3, 54.3, 54.0 I need to find the standard deviation of this list of data. 2. Homework Equations standard deviation= : s^2=\frac{\sum_{i=1}^n(x_i -\overline{x})}{n-1} Actually the standard...

A department store has determined that 25% of all their sales are credit sales. A random sample of 75 sales is selected and the proportion of credit sales in the sample is computed. a) What is the probability that the sample proportion will be greater than 0.34? my answer is: n=75 p=0.25...

Hey all. Im doing maths methods 5 (i live in Australia) and I've run into this problem. A university study investigated the increase in heart rates(measured in beats per minute) of people undertaking a particular exercise. The increases in heart rate were normally distributed with...

Hello everyone. He told us he could of course change the parameters which he will of the proofs we have been working on so I'm testing out some cases but I want to make sure I'm doing it right. Here is an example of a proof the boook had...

I am looking for a mathematical derivation for the idea that symmetry of the light beam path through a prism gives rise to a minimum deviation. Thanks.

Ok, so I'm sure that I worded the topic of this thread poorly, but I'm a little lost as to exactly how to explain my problem. As such, I'll just lay out everyting in some detail and hope those of you with more stats expertise will understand :o) The problem: * I have data from 5 subjects...

Ok I've got a maths exam on monday and one of the things that is going to be inside it is standard deviation. Problem is I don't get it one bit. I tried googling it but I didn't understand any of it. Could someone explain to me how I would find the estimated standard deviation for the...

I am working on a primatology project where I need to find a way to measure and plot the (somewhat arbitary) level of variation in behavior (ie from one individual to the next) within a single species and then compare it to another species level of variation. I have entered the data for the...

Can someone let me know how to compute the standard deviation on the TI-83.:smile: Thanks, Home Decoration

Just a quick question as I'm writing up my coursework. I'm calculating the standard deviation of a sample, my data is rate of reaction defined as \frac{1}{time} \times 10^{-3}. So my input data is say 0.847, but the absolute value is 0.000847. The standard deviation formula returned a value...

I have no idea how to start this problem or what equations I would need, if any. Below is the problem, and after that, I include my failed attempts at this problem. The problem: ------------------------------------------------------------------------ Students at Eastern Illinois University...

Let us assume that X has Bernoulli distribution, with P(X = 1) = p and P(X = 0) = q = 1 - p. Of course, E(X) = p and Var(X) = pq. Now, since pq < 1, standard deviation is bigger than variance. I have got the following question: Does this fact make standard deviations and theorems based on...

Umm its tough to see so I'll write the question too... The standard deviation of the annual growth rates of a mutual fund is an indicator of how volitile or risky the fund is. Determine the upper and lower limits of the annual growth rate for each fund, such that there is a 0.75 probability...

Hi everyone, I was wondering what the mathematical relationship between temperature and standard deviation in energy is. As I understand it, temperature is energy in random motion, and some sets of random data have a standard deviation from the "average". So how would the temperature of, say...

I know that RAD is used to expression precision, and I know the formula for it: Per mil RAD = (abs. deviation)/mean X (1000) for parts per thousand. Once you find the relative average deviation--this number in ppt--what is the significance of it? What is it supposed to tell you about the...

You heat an ideal material (solid, liquid, gas) and it emits electromagnetic radiation, with a spectral energy distribution (SED) following that of a "black body", per Planck. You heat a homogeneous real material (a lump of iron, a body of water, some hydrogen; things like dust with a wide...

hello :-p i want to ask about the deviation of real gases under low temperature and high pressure. :-p my reference book states that carbon dioxide deviates more than nitrogen and hydrogen,this is because the order of boiling points of is decreasing from carbon dioxide to hydrogen.this...

T = \sqrt { \frac{2d} {g} } Therefore (and I had to come up with this on my own because I could not find it on the internet :smile:) D = \frac{t^2 * g} {2} But I cannot find the logic in why the time equals 2 times the distance over the acceleration of gravity on earth. Now, I do...

\textit{To get an estimate of your uncertainty, compute the standard deviation. My 4 distances are 150, 120, 100 and 100 parsecs (pc)} The average of my 4 distances is \[ \bar {x}=\frac{\sum\limits_{i=1}^n {x_i } }{n} \] \[ \bar {x}=\frac{150pc+120pc+100pc+100pc}{4}=117.5pc \]...

If you tossed two coins simultaneously 400 times, would you expect the standard deviation to be greater or less than it was 40 times? I think tossing 2 coins 400 times would give a greater standard deviation because the sample size is larger so the standard deviations can be quite far from...

Standard deviation? COIN TOSS HELP! I tossed a coin 20, 30 and 50 times are recorded number of heads and tails and to get the deviation I first subtracted the expected from the observed for both heads and tails then I squared this value and divided it by the number of events and then toook the...

*I have already posted this in another forum, but re-read the rules regarding homework questions.. Mods, I hope this is ok* Hey guys, I've got this question from my Statistics Homework and wondered if someone could point me to a website or supply some advice as to how to begin to solve the...

Here's the question: so, I said the mean (X) of delta is 0.0015 and the standard deviation (S) of delta is 0.000092 X_d=0.0015, S_d=0.000092 X_l=2.000, S_l=0.0081 I said Z=d/l\ thus\ X_z=X_d/X_l and the S_z^2=(C_d^2+C_l^2)/X_z^2 So, I did the following...

Well in physics lab we just did a lab where we calculated the acceleration do to gravity,this didn't include the air resistance, so the ligther stuff shouldn't be perfect. We took video of stuff falling and then put the data from that into mathematica and fitted a quadratic equation to it and...

1. If a school offers 3200 separate courses and a survey of these courses determines that the class size is 50 with a standard deviation of 2, what would one expect for the average and standard deviation of a subset of 50 of these classes selected randomly? 2. In a survey to estimate the...

Changes to Standard Deviation?? How many of you know that Standard Deviation has changed. It used to be:\sqrt{\frac{\Sigma(x_i - \overline{x})^2}{n}} And now it is:\sqrt{\frac{\Sigma(x_i - \overline{x})^2}{n - 1}} It is the Variance of data but square rooted: s^2 = \frac{\Sigma(x_i...

Why is the standard deviation \sigma =\sqrt{\frac{\sum_{i=1}^{n}\left( \overline{x}-x_{i}\right) ^{2}}{n-1}} and not \sigma =\frac{\sum_{i=1}^{n}\left| \overline{x}-x_{i}\right| }{n} or at least \sigma =\sqrt{\frac{\sum_{i=1}^{n}\left( \overline{x}-x_{i}\right) ^{2}}{n}}? I suppose that it...

I am having trouble understanding this question, can somebody here please explain it to me... should be quite simple as this is only high school stuff. Calculate the angle of deviation at a glass-air interface for an angle of incidence of 65degrees and refractive index of glass of 1.55 ...

I was given an assignment dealing with finding standard deviation. From the example given, I was able to do the assignment and get the correct answers, but I still don't understand standard deviation or its importance. Could someone explain standard deviation to me, or at least point me to...

Hi I have to design an experiment to fidn how the angle of deviation of a light ray depends upon the angle between two mirrors. I've found what the angle of deviation is (change in velocity experienced by a light ray after one or more refractions) but I don't know how to create an experiemtn...

How far from the peak wave do objects emit electromagnetic radiation? Humans emit infrared radiation, but I read that we also emit some microwave also.

I am having trouble with this question. Let X equal the number of flips of a fair coin that are required to observe the same face on consecutive flips. (a) Find the p.m.f. of X. if found the p.m.f. to be f(x) = (\frac{1}{2})^{x-1} for x=2,3,4,... (b) Give the values of the mean, variance...

Help please?? To anybody that can offer a hand. <x>=5, Standard Deviation = 2, median Mx=4.5, Quartile1=4, Quartile 2=6, xmin=0, xmax=9. After a linear tranform: y= -2x+1. What are <y>, Standard deviation y, median y, Q1y, Q2y, Ymin, Ymax. I was given this equation for...

Can someone take a look at http://wps.aw.com/wps/media/objects/500/512494/supplements/Ch21.pdf and tell me how they go from Eq. (7) to Eq. (8)? I've tried this and keep getting additional terms.

We know that the standard deviation [sig] for a random walk, represented by a net distance d, to be approximately the square root of the total number of steps N, each of length L, from the origin. I. e., d~N1/2L~[sig]L. Does the angle attained after these steps also have a significant...