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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-6
votes
0answers
18 views

Need a simple formula for calculating customer value. [on hold]

Calculating the loyalty value of customers: $x=\text{total_purchase_cost}$ $y=\text{no_of_orders}$ $z=\text{no_of_successful_refer}$ $\max=100$ $\min=1$ Suppose a user have made a total ...
2
votes
3answers
853 views

from weighted average to single values

think about when you're computing a weighted average: you do something like W = sum(amount*weight) / sum(weight) Now I need to find every amount (amount0, amount1.....) starting from knowing the ...
-2
votes
1answer
36 views

What time should Celia aim for in her sixth race to make the team? [closed]

To be on the 1-km race team, Celia must have a mean time less than 5 min 50 sec in her 6 tryout races. Her times in 5 races are: 6 min 2 sec, 5 min 53 sec, 5 min 45 sec, 6 min, and 5 min 34 sec. What ...
0
votes
1answer
12 views

Calculating the average of percentages from fields which have a “weight” multiplier applied.

This is for some software I'm writing. I have a number of fields, all of which have a score input which allows a percentage of 0-100. Each field has a "weight" property, which determines its ...
0
votes
2answers
16 views

Define temperature by clustering with math operators

I can´t figure out how to cluster the temperature for the weather in 3 optimal cases: hot, mild, cold My data contains: air temperature(the average daily value), max air temperature(highest daily ...
7
votes
2answers
163 views

Is there a name (and use) for an average based on the unique values of a set of data?

Consider the following data points: $1, 1, 2, 3, 4$ I understand that... the average is the total of the numbers divided by the count of numbers in the set, the median is the central value based on ...
9
votes
4answers
2k views

How do I figure out what kind of distribution this is?

I've sampled a real world process, network ping times. The "round-trip-time" is measured in milliseconds. Results are plotted in a histogram: Ping times have a minimum value, but a long upper tail. ...
0
votes
0answers
21 views

Finding average as well as impact of quantity

I am new to this site, I am basically a developer and stuck at a logical mathematics portion. I have polarity of people sending email, so suppose p1 sent mail and mathematical polarity came out to be ...
41
votes
11answers
7k views

What is the average of no numbers?

I have two programs that both behave nearly identically: they both take in any numbers you give them and can tell you the average and how many numbers were given. However, when you don't give them any ...
2
votes
1answer
32 views

Average of a list of numbers, read one at a time

I have a dilemma Lets take the set $\{1, 2, 3, 4, 5, 6, 7, 8, 9\}$ If we wanted to calculate the average of this set we would add up all the numbers in the set $(45)$ and then divide by the total ...
0
votes
0answers
16 views

How can I calculate percent error with a denominator of 0? [duplicate]

I am using the MAPE formula, ABS(actual-forecast)/actual *100, but this raises problems when the actual values are zero. Is it possible to add 1 to the denominator and calculate this way? Would I get ...
1
vote
1answer
43 views

Why this process is nonergodic?

I am studying a tutorial on stochastic processes and there's an example in it which I don't understand anything of it. First of all there is this criterion for a mean-ergodic random process: For ...
1
vote
1answer
34 views

Could someone explain the notation of the average of quaternions equation?

The equation has some notation that is difficult to find the meaning for. It is equation (3) in the paper 'Quaternion Averaging' by F. Landis Markley, et al. on page 3 under 'The Average Quaternion'. ...
2
votes
1answer
32 views

Is tossing a die in 10 consequent days an ergodic process?

IT maybe an elementary question but I'm totally new to the concept. In Wikipedia, ergodicity is defined as follows: In statistics, the term describes a random process for which the time ...
0
votes
1answer
26 views

what's the difference between variable and process from a statistical point of view?

I'm reading a tutorial stochastic process: ergodicity and temporal averages and I'm totally confused. It is said that: Suppose an IID random process whose marginal PDF is Gaussian with mean ...
2
votes
1answer
137 views

what does `ensemble average` mean?

I'm studying this paper and somewhere in the conclusion part is written: "Since this rotation of the coherency matrix is carried out based on the ensemble average of polarimetric scattering ...
0
votes
0answers
47 views

what is the difference between statiscal averagre and average?

I'm reading a book on synthetic aperture radar and it is said that: The term $\sigma^{\circ}$ is the averaged radar cross section per unit area, also called the scattering coefficient or ...
0
votes
1answer
23 views

Combining percentages differences

I would like to know the difference between two approaches of combining percentages. I found an online example that match my situation; the example have been found in The University of Georgia page. ...
1
vote
1answer
47 views

How to summarize a big table of results? Average or Geometric mean?

I am writing a paper for a Computer Science conference and I have a big (way too big) table of results (times and some other measures) for different versions of an algorithm. I would like to summarize ...
0
votes
2answers
35 views

Average value of distinct combinations

Distinct combinations of 123 are 123, 132, 213, 231, 312 & 321. Adding those and dividing by 6 gives the average 222. Same goes for 246: 246, 264, 426, 462, 624 & 642. Added up and divided by ...
0
votes
2answers
27 views

Difference between the two ways of finding average winning rate over a period of time

Ok I might be asking something stupid, please bear with me, math is not my strong suit. This has to be a duplicate but I dont know how to search them. I dont even know how to word the title, kindly ...
0
votes
2answers
38 views

Explaining this inequality

In a proof I was working on today, I assumed this equation was true which lead to devastating results $$ \sqrt{\bar{x^2}} =\bar{\lvert x\rvert} $$ For instance, given the data 0 and 2, the left hand ...
4
votes
2answers
121 views

Average $lcm(a,b)$, $ 1\le a \le b \le n$, and asymptotic behavior

What is the average value for $\mathrm{lcm}(a,b)$, with $ 1\le a \le b \le n$, for a given $n$, and what is the asymptotic behavior? The $\mathrm{lcm}$ is the least common multiple. I have ...
1
vote
1answer
37 views

A specific kind of Moving average

The problem is : Consider the list consisting of the first n natural numbers without zero, ie from $1$ to $n$. We define the transformation "moving average" on the list of $n$ elements by ...
0
votes
1answer
19 views

compute a value based on goegraphic range from measuement devices

Today is one of those days when the correct method to calculate this escapes me. I have 3 fixed points on a map where measurement devices are located. These all track the same transmitters. A mobile ...
2
votes
2answers
93 views

weighing avg by columns vs rows outputs different results

First of all, I just know the basics of math, so please be patient. I have an overall score for a company with the product1 and product2. However when I do the overall for each criteria like ...
6
votes
2answers
5k views

How to add and subtract values from an average?

Say I have 100 numbers that are averaged: number of values = 100 total sum of values = 2000 mean = 2000 / 100 => 20 If I want to add a value and find out the ...
0
votes
1answer
24 views

Average score for a Quiz based on recent performance

A quiz always has 10 questions. Correct answer results in 1 mark. No negative marking. A user can take the quiz as many times as he likes. I want to show his 'Average Score' based on last 5 quiz ...
5
votes
3answers
2k views

What is the average of rolling two dice and only taking the value of the higher dice roll?

What is the average result of rolling two dice, and only taking the value of the higher dice roll? To make sure the situation I am asking about is clear, here is an example: I roll two dice and one ...
2
votes
1answer
49 views

Why is the average of a sum equal the sum of the averages?

I came across this website showing the proof of the above question in the Expected Value section. However, I do not quite understand why the probability of $xy$ becomes the probability of $x$ (or $y$) ...
0
votes
1answer
34 views

Intuition: Average vs. Average Rate of Change

I intuitively understand the examples below, but I don't see an "average" in the average rate of change (I see a ratio of two delta values). What is the relationship between the average (arithmetic ...
1
vote
1answer
10 views

Grading limitless variables

I am trying to calculate the quality of a triangle. Parameters are skewness, aspect ratio, and size. Skewness ranges between 0 and 1. Aspect ratio is the ratio of longest edge to shortest edge. ...
0
votes
0answers
7 views

How to show monotonicity of this weighted average?

I have a sequence of positive and increasing (in all of its arguments) functions , $\{f_i(x_1, x_2, \dots, x_M)\}_{i=1}^M$. I also have: $$ ...
1
vote
3answers
2k views

what is the difference between average and expected value?

I have been going through the definition of expected value in Wikipedia (http://en.wikipedia.org/wiki/Expected_value) beneath all that jargon it seems that the expected value of a distribution is the ...
-1
votes
2answers
23 views

Average Attendance [closed]

I need to find a monthly average attendance. 3 out of 4 weeks were not counted. Do I take the number from the one week that was counted and divide by 4 or just use that one number as the average?
1
vote
3answers
38 views

how do they calculate these following columns

I have these data: I am sorry the data is in Portuguese, and it is an image so I can't convert it to a table but the translate "probably" ( i am not a native speakers for Portuguese language) is: ...
3
votes
1answer
44 views

Expected value (mean) of function from polyline

Suppose we have a polyline that has such properties: It consists of n segments First segment's ends are (0, 0) and ...
0
votes
0answers
18 views

Understanding the convolution as a weighted average to eliminate noise $ s(t) = \int x(a) w(t-a) da$

I was reading Yoshua's Bengio [book][1] on convolutional neural networks and it has small section that described/explains the convolution in the context of estimating the location of a spaceship with ...
0
votes
0answers
9 views

Moving average where periods have unequal # of samples

I'm trying to compare a simple moving average approach to one that normalizes by the number of samples in a period to determine which is "more correct." Here's a representative piece of the data: ...
1
vote
1answer
105 views

Maximum and minimum average question

During a cricket match, India playing against NZ scored in the following manner: Partnership | Runs scored $1$st wicket$~~$ | $112$ $2$nd wicket | $58$ $3$rd wicket$~$ | $72$ $4$th wicket$~$ | $9$ ...
0
votes
1answer
64 views

SAT Math Question Confusion

I was doing a practice new SAT Test and was wondering exactly what this question is asking and how it got to the answer. Thanks!
0
votes
1answer
25 views

Five-year Annual Average vs five-year Weighted average maintenance costs for two car types

If we are comparing maintenance costs (M$) per mile (M$/m = Mtype) of two car models over a 5 year period, where the number of cars that are type (a) is much less than type (b), and the number of type ...
0
votes
2answers
94 views

Weighted Average Distance between 3 or more points

I'm trying to find out the average point between 3 or more points, given each distance that the end point is away from each of the other points. With 2 points it's easy, I believe the formula should ...
0
votes
0answers
28 views

List of graph data points, need accurate calculation/estimate formula for excel

So I'm working on a small project that will use a calculation in excel, I'm nearly there and the only piece missing is being able to accurately estimate a data point from the following set of data ...
0
votes
1answer
48 views

What does $h$ and $x$ represent in $2x+h$

I was asked to find the average gradient between $x=2$ and $x=5$ on the curve $y=x^2+3$. My method: Average gradient = $\frac{f(x+h)-f(x)}{h}$ $$=\frac{x^2+2xh+h^2+3-(x^2+3)}{h}$$ ...
1
vote
0answers
17 views

What kind of time series do I need?

I am trying to optimize a list of websites on which to purchase banner advertising using the following setup: For each banner ad impression I buy I am charged $0.001. When my ad is clicked it ...
1
vote
1answer
75 views

Average patients waiting time in dental office

At a Dental Office, patients come in at the rate of 20 per hour and, on average, are processed at the same rate. Patients wait in a queue till they are called up to the counter for registration. After ...
1
vote
0answers
29 views

Matlab, Extracting Particular Values from an Excel File

If I have a table of values in Matlab ( here I have a 40k rows, and about a dozen columns), how can I read only particular values from each row? My goal is to extract some of the values from each row, ...
0
votes
1answer
85 views

Unweighted Mean of Percentages

I have come across an interesting problem, which I'm sure there must be a standard solution to, but lots of Googling hasn't yielded much (which may mean I'm well off track...). I am trying to ...
1
vote
0answers
19 views

Averaging Models in Excel

I am working in Excel and have two sets of data points that come up with a percentage for the likelihood of a recession. I am wondering what the best strategy would be to combine these data points? ...