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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-3
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1answer
16 views

Quantitative Aptitude Average [on hold]

The average weight of a group of boys and girl is $38$ kg. The average weight of boys is $42$ kg and that of girls is $33$ Kg. If the number of boys is 25, then the number of girls is?
1
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0answers
10 views

Does Averaging the score from correlation across multiple variables yield a more accurate correlation score?

This may be a beginner question but I am making a application which I using to do correlation research to be used in financial markets. The application pulls in different data sources and compares ...
5
votes
2answers
444 views

Find the average value of the function…

Find the average value of the function $$F(x) = \int_x^1 \sin(t^2) \, dt$$ on $[0,1]$. I know the average value of a function $f(x)$ on $[a,b]$ is $f_\text{avg}=\dfrac1{b-a} \int_a^b f(x) \, dx$, ...
-1
votes
0answers
29 views

What are greatest and least average values? [closed]

I'm working on a school assignment in which I've a series and I've to compute these two values, but I can not find the meaning of these terms. I tried searching online resources but wasn't able to ...
-2
votes
0answers
34 views

Describe the behavior of the average temperature difference of Earth as a function of time. [closed]

So I am having trouble with this question for my ENVS class. I am not sure what type of formula to use or where to start, in no way or form does my professor give an example in our notes. Here is the ...
3
votes
4answers
149 views

Removing my averages

thanks for your time and apologies if this is far too simple for this group. I am trying to remove my average from a total average. Meaning: The total average for a subset of data is 55. I am 29% ...
0
votes
0answers
22 views

Aproximation for the variance (sum)

Given that we know The mean of a population $\tilde W(t) = \sum_{i=1}^{n}f_{i}(t)*W_{i}$ The variance of the population in the previous step $Var(0) = \sum_{i=1}^{n}f_{i}(0)*(W_{i}-\tilde W(0) )$ ...
0
votes
1answer
19 views

Find upper bound from average value

I have been give a function, its average value, and the lower bound of an interval, I am trying to find the upper bound but I am a bit lost on how to do that. Here is what I have so far: $$ f(x)= \...
0
votes
1answer
11 views

achievability of average

Out of a textbook. Informally, the goal is to show that if from a given set of values ($2^n$ many values) in the range of $[0,m]$ (for fixed $m,k$), more than half are less than $m\cdot (1-\frac{1}{2^...
-1
votes
1answer
28 views

Average distance (maximum norm) from origin to the nearer of two random points in a unit square

I got a unit square, the origin (0,0) and two random points which are uniformly distributed on the 1x1 unit square. What is the average distance in maximum norm from origin to the nearer of the two ...
1
vote
1answer
61 views

2 trams are coming every 5 and 10 minutes. On average, how long do I have to wait for any tram to come?

I want to follow the approach from Christian Blatter here 3 trams are coming every 10, 15 and 15 minutes. On average, how long do I have to wait for any tram to come? using "the assumption that the ...
0
votes
3answers
47 views

What is the relationship between average distance between 2 random points in a cube, with min and max?

I wrote a computer program to simulate the minimum, average, and maximum distance between $2$ random points in a unit length cube (such as $1$ cubic foot). The minimum possible distance is $0$ and ...
0
votes
2answers
23 views

Trying to Calculate Averages for Record Types

I am trying to compute the averages for the following (3) types of records but not sure if I am getting the correct results: 387 Total record count (valid/invalid/other) - created by 45 total users ...
0
votes
2answers
30 views

Find the average when zero is also there [closed]

If a set $A = \{0,1,10\}$ . What is the average? Is it $\frac{(0+1+10)}{3}$ or $\frac{(1+10)}{2}$.
1
vote
1answer
35 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. ...
0
votes
1answer
24 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 ...
0
votes
1answer
12 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= (...
0
votes
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
vote
0answers
30 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 ...
1
vote
0answers
25 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
votes
3answers
120 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
vote
1answer
20 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 $f(x)=Asin(kx+c')$ ...
1
vote
0answers
32 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 ...
0
votes
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
38 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 ...
-1
votes
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 ...
0
votes
0answers
11 views

Normalize and Average weighted

Everyday I receive a data of three variables (neutral, negative and positive). ...
0
votes
0answers
23 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
votes
0answers
43 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 ...
0
votes
0answers
27 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 ...
0
votes
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 ...
0
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0answers
35 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: ...
-1
votes
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
56 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 ...
0
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0answers
31 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
vote
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 ...
1
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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 ...
0
votes
0answers
17 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
42 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
votes
1answer
28 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 ...
0
votes
2answers
48 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
votes
1answer
28 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 ...
0
votes
2answers
45 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
votes
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
votes
2answers
36 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 ____ ...
1
vote
0answers
19 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 ...
0
votes
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
votes
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
votes
1answer
34 views

Function to determine a set of numbers are balanced

Given the following data, based on a 0-100 scale ...