The sum of several numbers divided by their count nicely summarizes the overall size of the numbers involved in a single value.
4
votes
2answers
503 views
Real world examples for Mode in Statistics
I am looking for some real world examples for mode in Statistics involving topics which students like say Football or Social networks. Also they need to clearly identify differences in the usefulness ...
0
votes
1answer
15 views
Calculate the new average using standard deviation?
This is for a programming exercise. I have:
the last average value
the last standard deviation
the total number of values
I need to be able to add a new value to my average without knowing the ...
1
vote
1answer
192 views
math distribution of averages and distribution of standard deviation for comparison of bytes
Let me change my question:
I have a sequence of 512 numbers (these 512 numbers can have a value between 0 and 255) (in computer mode these numbers can be between 00000000 and 11111111 (bits)). For ...
1
vote
1answer
2k views
Average of multiple vectors
I have more than two vectors (these are 2D vectors) and I want to calculate the mean vector. What is the correct way to do it?
All my vectors share their origins at (0,0).
1
vote
1answer
51 views
Algorithm to separate an array of numbers into “low”, “medium” and “high” ranges
this is my first post on Math-Exchange. I'm a programmer, and I work with object-oriented algorithms, but when things gets too "algebraic" I get stuck. So I thought I'd ask over here.
I need to ...
2
votes
2answers
150 views
Least Squares Fit
So here's the question:
Given a collection of points $(x_1,y_1), (x_2,y_2),\ldots,(x_n,y_n)$, let
$x=(x_1,x_2,\ldots,x_n)^T$, $y=(y_1,y_2,\ldots,y_n)^T$,
$\bar{x}=\frac{1}{n} ...
0
votes
0answers
19 views
How to find the average in the given labels?
I generated 11 random variables follow the Poisson distribution. I used lambda equal to 5.
The data that I got is following :
0.00673794699908547
0.0336897349954273
0.0842243374885683
...
0
votes
2answers
32 views
Quadratic and geometric average
I'd like to find the find the quadratic average and the geometric average. To do this I have these informations :
The standart deviation, the arithmetic average and the number of values.
I know the ...
1
vote
1answer
44 views
averaging time it takes to complete a project
Consider a project consisting of four activities A, B, C, and D.
a) A and B, the first activities of the project, can be started simultaneously.
b) C can be started only after A is completed.
c) D can ...
0
votes
2answers
42 views
Is there another name for power mean, where p=1/2
What would you call this type of average?
$\left(\frac{1}{n} \sum_{i=1}^n \sqrt x_i \right) ^ 2$
0
votes
1answer
123 views
Need algorithm to take “max” of scores, but with “quality” weighting
I have an application where I get a small number of scores from medical tests (the same test repeated a few times) and I need to combine them. Normally the highest score would "win" in this ...
0
votes
0answers
18 views
Comparing data to find the “consistently lowest” subset of data.
I am currently faced with a set of data representing the time taken to move and click on an object, in relation to the distance and size of the object (see Fitts's Law if curious but that's ...
0
votes
0answers
30 views
How many times you have to do something to get an accurate average.
Ok well i play a lot of online games and with the one I'm currently playing my brother and I got into a discussion on how to make gold the quickest. So this question is based on killing and looting. ...
1
vote
1answer
62 views
Derivative of a 'weighted average' of decreasing fractions
I'm having some trouble showing the following statement (which intuitively seems to hold):
Suppose I have a series of fractions indexed by $i$ , each of them a function
of $N:f_{i}\left( N\right) ...
1
vote
4answers
33 views
Finding mean of $n$ consecutive numbers using a shortcut
I am working on the following question:
Let us say we have $n$ consecutive numbers labelled $x_1$ to $x_n$. I want to find the average of these. The quickest way to do this seems to be ...
-3
votes
1answer
41 views
Quiz averages, statistically fair? [closed]
I was wondering if it is statistically fair to take the percentage of three separate quizzes that are not worth the same amount of points and divide it by 3 to take an average grade. For example, quiz ...
0
votes
0answers
29 views
How to calculate avaerage of the average
I am having data of 10 schools, each school is having different no of sections. Each section students attended different no of computer classes. How to calculate the average no of computer classes ...
0
votes
1answer
54 views
Find out Average and Percentile from the Histogram
Below is my Histogram information-
{178=18, 213=1, 114=76, 139=5, 131=10, 176=13, 95=229, 1444=1, 206=5,
192=4, 227=2, 185=12, 67=14, 199=4, 148=11, 124=21, 75=226, 1431=1,
123=29, 157=16, ...
1
vote
1answer
28 views
How to figure out that 95 pecentile of time calls came back within certain milliseconds
I am working on a project in which I am supposed to do profiling on our REST Service. And after that figure it out how much is the ...
1
vote
1answer
51 views
Expected value of a multivariate distribution
Given this random vector:
$$
\mathbf{x} = \begin{bmatrix} x_1 \\ x_2
\end{bmatrix}
$$
And this probability distribution function that takes it as argument:
$$
f_\mathbf{X}(\mathbf{x}) = ...
1
vote
2answers
66 views
Calculating new vector positions
I'm using the following formula to calculate the new vector positions for each point selected, I loop through each point selected and get the $(X_i,Y_i,Z_i)$ values, I also get the center values of ...
0
votes
0answers
34 views
Turn any shape to circle
I'm looking at trying to calculate and re position 3d vectors to align in a new position to form a circle.
I've achieved this already however only when all points are evenly distributed in the same ...
1
vote
1answer
63 views
Calculate vector position
I'm trying to calculate & move vertices to their average "radius" and form a circle from these new positions.
Example: I have 8 vertices selected, I have a little script in Maya that will iterate ...
0
votes
0answers
78 views
Standard deviation of the weighted mean
How do you find the standard deviation of the weighted mean?
The weighted mean is defined: $\bar{x} = \frac{\sum{wx}}{\sum{w}}$
The weighted standard deviation (since it is not specified, I take it ...
0
votes
1answer
96 views
Average Slope of 4 Slopes
I want to calculate tha Average Slope of 4 Slopes, but Im not too sure if this will require me to calculate the Average error when I do calculate the average of the 4 slopes.
Im obviously calculating ...
2
votes
1answer
47 views
What is this physics simulation formula doing?
I have encountered a piece of code that performs a physics simulation of a moving projectile. I'm trying to understand what the mathematical basis is for a bit that looks like this:
$$
d_1 = f(x)
$$
...
1
vote
2answers
48 views
Merging/averaging percentages
This may be a very simple question, but I'm not even sure what the correct terminology is for the procedure I am trying to do so I wasn't able to find anything else here...
The scenario is that I'm ...
1
vote
1answer
53 views
Why 1 / (average of series) $\ne$ average (1 / series)
I have series of two stocks prices. Let's say that stock 1 has prices:
$A_1$, $A_2$, $A_3$, $A_4$, ..., $A_i$ (where $i$ is time)
And stock 2 has prices:
$B_1$, $B_2$, $B_3$, $B_4$, ..., $B_i$ ...
0
votes
1answer
57 views
Working with average numbers and finding unknown variables?
There is this question I was approached with and I am absolutely stumped on where to even begin to solve it. It goes like this:
Based off the following 4 equations, find the average of $x_1$, $x_2$, ...
0
votes
1answer
73 views
Most Probable Average Marks
There is a class of 40 students. A professor conducted a quiz on which consisted of 10 Multiple Choice Questions. Each question had 4 options, out of which only one is correct. Each question carried 1 ...
0
votes
2answers
71 views
How to recognize ellipse/ellipsoid from random points? UN-weighted average?
Suppose we are getting random points in 2D (or 3D) which tend to be on ellipse (or ellipsoid). We can't guarantee points are uniformly distributed over ellipse (ellipsoid surface).
The task is to ...
0
votes
2answers
91 views
Average percentage of percentage
I ran a survey on my website where users marked a checkbox for what % they did X. Something like this.
...
5
votes
4answers
759 views
How can I calculate “most popular” more accurately?
I'm developing a website at the moment.
The website allows users to "rate" a post from 0 to 5.
Posts can then be displayed in order of popularity.
At the moment, my method of calculation is pretty ...
6
votes
4answers
100 views
Is there a way to get an average that weights each item inversely based on distance from the mean?
I'm not sure how to phrase this, or even if such a thing exists. Sorry!
I have a bunch of data points, which are mostly pretty tight. Each group should hone in on a specific point in space. ...
0
votes
1answer
44 views
How to average numbers with high standard deviation
I have a set of n numbers that I need to review and come up with the closet average. The set of numbers may or may not have a high standard deviation. Below is an example...
Set of numbers..
...
1
vote
1answer
78 views
Intuition calculating average price change
Given two products p1 and p2, each with a price per single unit and an amount per year. The question is to calculate the average change in price for both products combined.
...
1
vote
0answers
34 views
Deconvoluting linear combinations of unknown distributions
Summary
I am trying to deconvolute the distribution $T(x)$ of a population's $x$ parameter into sub-distributions ($P(x)$, $Q(x)$, $R(x)$ ...), of which I don't know the form (only that they have ...
4
votes
5answers
150 views
what is the argument for not using the average of an average?
I want to disprove someone's calculation of percentage of cash sales for a year by taking summing percentage of cash sales by month and dividing by 12. I sense the correct way is to take total cash ...
1
vote
2answers
88 views
Average limit superior
Let $\mathcal{l}_\mathbb{R}^\infty$ be the space of bounded sequences in $\mathbb{R}$. We define a map $p: \mathcal{l}_\mathbb{R}^\infty\to\mathbb{R}$ by
$$p(\underline x)=\limsup_{n\to\infty} ...
0
votes
1answer
58 views
How to calculate variance on spending?
My maths is a little rusty, but I understand how to calculate variance in general. A colleague asked me if I knew how to calculate the percentage variance on budget spending.
Given this example:
...
2
votes
3answers
147 views
Averaging the values of $\cos x$ over one period
I'm calculating the average value of $\cos x$ by dividing the period $[0,2\pi]$ into ten intervals which means that I should be looking for the average of 11 results. What I get is approx. 0.09. The ...
2
votes
0answers
19 views
Inference the time a process would take depending on the number of threads
I have several datasets consisting on:
Number of threads n
Start process time t1
Stop process time ...
1
vote
1answer
237 views
Average proportion for proportions with different denominators
Say I have an experiment in which subjects are asked to respond to some stimulus. Their responses are transcribed and coded, first as "Valid/Invalid", and then for the valid responses, ...
0
votes
0answers
65 views
Histograms - mean or median?
Is it better to use the mean or median when looking at averages in a histogram? I'm thinking median, but I'm not quite sure why.
1
vote
1answer
57 views
Calculating expected value
Here is the problem.
In a game(shown below) with the marker in the center on each turn the marker moves to a neighbouring region with all positions equally likely and the player collects the cash ...
1
vote
1answer
33 views
finding average price of two lots of shares
Sorry, not a math guy, this might be an overly simple question for the lot of you, but it's a calculation that I'll have to do a lot possibly, so please show me the best way to do it. If I have $1265$ ...
1
vote
1answer
26 views
Generating statistics from data samples, that are of snapshots.
My question is part math part computers but I need more of the math answer then a computer answer. I am going to be grabing snapshots of a moment of time on how a computer is performing. Because of ...
3
votes
1answer
30 views
How do I average a new number into an established percentage if I know the number of items?
This seems like something I should be able to do but I can not for the life of me figure it out. I'm writing a program to calculate an average score; let's say that my data looks like this.
x = ...
1
vote
2answers
90 views
How can I find the average y value of a function on a given domain?
Lets say that $f(x) = (10 - x)\ln x$.
Over the domain: $1 ≤ x ≤ 10$.
How can I find the average value of $y$ over this domain and what is that value?
1
vote
1answer
66 views
Calculating average customer turnover
I am currently coding a script which displays data for a company intranet. I am stuck with a question that seemed pretty simple, but turned out to give me headaches.
We have the following scenario:
...
