The sum of several numbers divided by their count nicely summarizes the overall size of the numbers involved in a single value.

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1answer
33 views

Which is the proper way to calculate average speed.

Let's say we have a graph, a distance-time graph, and there are couple points on the graph. The points are connected to each other with different slopes, so with different speeds between the points. ...
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1answer
22 views

Detecting unusual activity

How would one go about detecting unusual order flow in an intelligent way. That's very broad, so let me narrow it down. I have a trading system with clients entering number of orders every day. At ...
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1answer
10 views

Calculating the average with Limited memory and without using the count

I am having a flow of numbers on an embedded device, and I cannot store the flow of numbers and would like to calculate the average. I have checked around and found one way was to do like this Avg= (...
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0answers
8 views

Weighted mean / average where you reward the lowest value - cost - distance

Best I've several weather-station (200), placed across the country (508 municipalities). Now, I would like to prescribe the weather info, e.g. temperature, to each of the municipalities of that ...
1
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0answers
28 views

What do attendance figures tell me about regularity? What does the average tell me about individual attendance?

Suppose I have a group of $N$ people, attending a series of $M$ events, and (for simplicity) let's assume the overall attendance happens to be the same at each event, say $A$ people (ranging between 1 ...
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1answer
22 views

Variance of exponential moving average

I'm not quite sure what the form for the rolling recursive variance should look like. I have that the recursive average is $m_t = \alpha x_t +(1-a)m_{t-1}$. Then would the rolling recursive variance ...
3
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3answers
105 views

Average value of $e^{-x}$ from $0$ to $\infty$

I just signed up for this site so I hope I'm doing this right. I've been having trouble wrapping my head around the average value of the function $e^{-x}$ from 0 to $\infty$. I know that the average ...
1
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1answer
16 views

Average amplitude of the sum of N sines with random phase differences

We have N functions of the form $asin(kx+c)$ Their $a$ and $k$ values are the same their $c$ is a random number between $0$ and $2\pi$ $f(x)$ is the sum all N functions I know $f(x)=Asin(kx+c')$ ...
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0answers
28 views

Exponential smoothing and variance

I have a time series, let's denote it as $X_t$ (a series of prices). We exponentially smooth the data to obtain another time series, an exponential moving average: $EMA_t$. My question is how do I ...
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2answers
28 views

Volume and Average Height

How do you calculate the average number of floors of buildings across a city block when all the buildings are varying heights. Followings in a listing of what the area looks like and the number of ...
0
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0answers
36 views

How can I calculate accuracy of an estimate based on a subset of data?

For example, say I'm trying to determine the average number of steps taken in a day for a population of 100M people. I know the exact number of steps for a random 25M subset of the 100M group (2500 ...
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1answer
21 views

How can I get the average angle from a set of three points?

Please forgive me, but I'm not mathematically inclined and i'm trying to solve a problem for a video game i'm developing. My levels are composed of vector shapes and i want to find out what the ...
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0answers
10 views

Normalize and Average weighted

Everyday I receive a data of three variables (neutral, negative and positive). ...
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0answers
20 views

Boosting v. weighted average

I have been watching an MIT online Artificial Intelligence lecture by Prof. Winston about boosting. The boosting technique uses complicated maths to combine the results from several weak predictors to ...
2
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0answers
42 views

What is the average maximum value of a set of random numbers? [duplicate]

Let $a_1, a_2, a_3, \ldots, a_{10}$ be ten randomly chosen real numbers in the interval [0,1]. Let $m$ be the maximal value out of these 10 numbers. What is the expected value of $m$? (i.e. If i ...
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0answers
25 views

Anyone have any good ideas on how to average 2D directions?

Directions, being a cyclical quantity (i.e. if you keep increasing the value, you'll eventually end up back where you started) can't be averaged out like regular numbers. For example, say I have 2 ...
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0answers
17 views

The average value of f on region R (double integrals)

If I am given f(x,y) and I calculate the average of the region given by the formula in this image should the average always = (min of f(x,y) +max of f(x,y))/2. I think this is only the case if the ...
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0answers
33 views

How can I calculate my current average for my class?

I'm trying to do some what-if scenarios for one of my courses and I'd like someone to double check my work. The grade breakdown is as follows: ...
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1answer
19 views

Buying forecast

I have a set of items. In 2013, I bought x of a certain item, in 2014 I bought y, and in 2015 I bought z. In many cases, I only bought the item in one year, like: ...
0
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1answer
55 views

What is the name of this formula??

Let formula_a = lambda array: sum(array) / len(array). We may rename this formula to be average or ...
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0answers
22 views

How do you set the half-life of an exponential weight?

I'm trying to follow the process described in a paper, where they smooth a time series using exponential weights, for which I'm using the formula $z_i=\lambda \bar x_i + (1- \lambda) z_{i-1}$, as ...
1
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1answer
16 views

How is the first term weighted in an exponential smoothing, or exponentially weighted moving average?

I'm working with exponential smoothing for a series, using the formula $z_i=\lambda \bar x_i + (1- \lambda) z_{i-1}$, as explained in this wiki article. Using this method, should $z_{1}$ be defined ...
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0answers
17 views

Confused by simple risk problem

I am having troubles understanding this basic problem and would like to see if anyone could help me out. I have two boxes: one red, one blue. Depending on what box I pick, I have the potential to ...
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0answers
16 views

Can distributions scale to any given time scale?

I am working with some colleagues to set up alerts based on call center data, and I feel that something is wrong with how it is currently being done, but I'm not sure what exactly, or how to explain ...
0
votes
2answers
41 views

Bit increase when averaging?

I have a given number $N$ of binary numbers, that are stored using a given number $B$ of bits. $B$ is the same for all the numbers. For example, thease values where $N = 4, B = 4$. ...
0
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1answer
26 views

Applications of mean and standard deviation

If I have this set of numbers: [9,7,5,5,4,4,4,2] We know that: mean = 5 variance = 4 standard deviation = 2 But is there an application/formula of standard ...
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2answers
45 views

How do I calculate a combined data error?

I have a time series of data points read from an instrument, I also get an estimate of the error ($\sigma$) for each of these readings. e.g. $10.12 \pm 0.05$ $10.09 \pm 0.02$ $10.20 \pm 0.12$ ...
0
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1answer
25 views

The average of 38,84,63,45,32 and n lies between 50 and 60.If n is an integer greater than the average of the above numbers, then n lies between?

The options are 53 < n <97 50 < n < 100 52 < n < 98 I added the values along with n to get 43.66 + n/6.I then tried plugging in values from the options and tried arriving at ...
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2answers
43 views

A worker is told that only $5\%$ of all workers make a higher wage. If the wages are normally distributed, what is the average hourly wage?

So let's say a worker earns $\$16$ per hour at a plant and is told that only $5\%$ of all workers make a higher wage. If the wages are normally distributed with standard deviation of $\$5$ per hour ...
0
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0answers
16 views

How to determine a formula for an index of compliancy

I hope you will be patient with the inarticulate question of a non-mathematician. It's hard to get an answer when you don't even know how to ask the question. Here the contest: Let's say that I have ...
0
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2answers
35 views

Average time between successive occurrences of earthquakes?

In any given year, the probability of an earthquake greater than Magnitude $6$ occurring in the Garhwal Himalayas is $0.04$. The average time between successive occurrences of such earthquakes is ____ ...
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0answers
17 views

Average Value of a Line Integral

I'm having quite a hard time calculating the average value of a line integral. Given the surface $f(x,y) = \sqrt{16 + 36y^{2/3}}$ and the curve $y = x^{3/2}$, I need to calculate the average value of ...
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0answers
9 views

Average discount give for product line

I have been out of school for entirely too long to remember how to build this equation. I am trying to calculate the average discount given for our entire product line, that is sold over 4 distinct ...
0
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1answer
35 views

Average cost of units over time

I buy and sell units at varying price and I always have a varying stock of units bought in different batches at different prices. I always keep the current_price and the current_volume and I base my ...
0
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1answer
34 views

Function to determine a set of numbers are balanced

Given the following data, based on a 0-100 scale ...
2
votes
2answers
36 views

Is there a name for the way I am averaging the cost of cards?

My buddy and I were discussing different ways of deciding how much mana to include when constructing a deck. Without thinking much about it I used a method of finding the average converted mana cost ...
1
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1answer
33 views

Weighted average of multiple weighted factors

Lets say a factory machine runs as follows: Day 1: $3$ widgets per minute $\times 1000$ minutes $\times 1$ kg per widget $= 3000$ kg. Day 2: $5$ widgets per minute $\times 800$ minutes $\times 1.5$ ...
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2answers
23 views

Reporting numbers that vary

I'm timing how long various parts of a computer program takes to run, with the intent of including this in a research paper. There are fluctuations in the timing based on the usual things inside a ...
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0answers
20 views

What is the appropriate way to average a set of slopes?

I have a set of line slopes (output from linear regressions) and I'd like to combine them to yield some measure of the 'slope' of the set. However, simply taking the mean of the numbers doesn't make ...
2
votes
2answers
102 views

How do I find the average of top list items? [closed]

Here's the situation: I have a lot of "top lists" like so: list1: iPhone 6 Galaxy S5 LG G4 list2: Galaxy S5 OnePlus One iPhone 6 LG G4 Nexus 5 list3: LG G4 Galaxy S5 Nexus 5 And so on... ...
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0answers
8 views

Another name for mode frequency

Is there another term for the number of times the mode number occurs in a list/array of numbers or 'the frequency of the mode' in a list/array of numbers? Apologies if this has been asked before - I ...
1
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1answer
23 views

Looking for an equation that reflects the majority of a collection

I'm working on a computer program, part of which involves sifting through large collections of numbers (by large, I mean 16 million+ numbers). I expect these collections to almost entirely be composed ...
1
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1answer
18 views

Averaging several factor of multiplication function

So, I have these kind of equations: $k_{A_1}*k_{B_1}*k_{C_1} = f_1$ $k_{A_2}*k_{B_2}*k_{C_2} = f_2$ ... $k_{A_7}*k_{B_7}*k_{C_7} = f_7$ What I have is $f_1$,$f_2$,...$f_7$ Is there any way to get ...
3
votes
3answers
54 views

Why this statistical equation is true?

Pardon my ignorance. I also don't know how to properly show the equation. So I attached URL of latex... Why this equation is true for any real number $k$, when $\overline{X}$ is average of individual ...
0
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1answer
38 views

Integrated average value of a multivariate function doesn't match average obtained through simulation.

So, recently I have been trying to calculate the expected area of a convex cyclic quadrilateral with perimeter $1$. Nonetheless, I will only post what's relevant to the issue - the fact that the ...
0
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2answers
60 views

The average age of 30 boys in a class is 16, including the teacher it is 17. What is the teacher's age?

The average age of $30$ boys in a class is $16$. If the teachers is included the average increases by $1$. What is the teacher's age? Options: $37$ yrs $30$ yrs $47$ yrs $57$ yrs None of these ...
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0answers
11 views

Weighted Average Using Rankings

So I have this data and I've ranked each category for each person. The best being 1. I can average them , just add up and divide, but I need to weigh them. If I weigh them like normal: ...
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0answers
28 views

Expected waiting time - simplified

I need some assistance with a calculation I'm trying to do. I have access to surgery waiting times data (date arrived, date completed) and I want to figure out the expected waiting time for a new ...
0
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2answers
24 views

Mean value of positive numbers in an arbitrary set of numbers

I have a set with an arbitrary amount of positive and negative numbers. Now I want to calculate the mean value of all numbers inside the set which are greater than $0$. Is there a mathematical way of ...
0
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4answers
24 views

How do you calculate a rolling average speed?

I am making a speedometer for my bike with an arduino and I have got it to display speed now I want to display average speed. But I'm struggling to think of how to do it. The speed is checked 1000 ...