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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15 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
13 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 ...
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2answers
40 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 $N = 4, B = 4$. ...
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1answer
21 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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37 views

How to find average distance of several points to one specific point.

I have a math project and I need to find the average distance of random houses to my school, I have no idea where to start and would like a little help. Thanks!
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1answer
42 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. $10.12 \pm 0.05$ $10.09 \pm 0.02$ $10.20 \pm 0.12$ ...
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1answer
12 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
39 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 ...
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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
32 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
14 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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5 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 ...
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1answer
34 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 ...
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1answer
31 views

Function to determine a set of numbers are balanced

Given the following data, based on a 0-100 scale ...
2
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2answers
35 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
25 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 ...
0
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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
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2answers
56 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
22 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
15 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
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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 ...
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1answer
36 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
46 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
9 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
24 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
23 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
21 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 ...
0
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2answers
24 views

General forumla for taking running average of a running average?

Let's say I have an array of $N$ numbers: $n_1, n_2, .... n_N$ I then calculate a running average of those numbers, by averaging $A$ numbers at a time, which will result in the following array: ...
0
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1answer
17 views

Calculate new average from two other averages with its respective totals/counts

I have the next film named Blade Runner and it has two version (director cut and theatrical cut) and I rate the director cut with a 7 and the theatrical cut with a 8, so the average would be: (7 + 8) ...
0
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1answer
32 views

Midpoint between two real numbers

Well, it's quite clear that if I try to count mean average of any two numbers, I always get the midpoint. Is it really the whole intuition behind this concept? Or is there something hidden behind this ...
0
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1answer
25 views

Calculate average lifespan

We want to calculate the average lifetime of our customers. For each customer we know when they joined, whether they are still with us and if not, what date they left us. Our company has exponential ...
0
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1answer
14 views

Mixture & Alligation problem

In what ratio must a person mix three kinds of wheat costing him 1.20,1.44 and 1.74 dollars per kg., so that the mixture formed is worth 1.41 dollars per kg? a)11:77:7 b)12:7:7 c)ratio other than a ...
3
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4answers
66 views

Determine drug concentration over time, given its halflife and dosage

I want to calculate which of two doses is going to have the most active ingredient over the total time of an experiment. So as an example let's say I have a drug which has a halflife of 5 hours, and ...
0
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0answers
19 views

Determine contribution percentage

I'm trying to determine the individual category percentages once their weights have been applied. The easiest way to describe what I'm asking is to show my workings: ...
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0answers
28 views

Median of medians vs. single median

I have 10 sets. Each set corresponds to a user. Each set contains a different amount of floating point numbers. Each such number corresponds to a response time (of a user). Now I would like to ...
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1answer
21 views

Calculate average time of person in system when ins and outs are roughly equal

I have a system that has people going through a sensor for in, a sensor for out. I'm measuring ins and outs through the day, ...
1
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1answer
56 views

How can I curve a test grade knowing only the average and the highest score?

I am trying to get a raw score for my test grade, but I don't know anything about the distribution of test grades; all the information I have is the average and the highest score (and of course my own ...
1
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0answers
13 views

Do I need to calculate the weighted average in these cases?

I'm aware of the concept of calculating a weighted average but the data I'm working with is confusing me. I couldn't find any similar examples when I did a search. Here's an example. We have a number ...
0
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2answers
60 views

A can do a job in three hours, B can do it in 4. Hjow long does it take them together?

As it says in the question: if one person can do a job in 4 hours, and another can do the job in 3 hours, how quickly can they do the job together in they can work together? My attempt was this: ...
0
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0answers
10 views

Does (messing up) FIFO affect average cycle time?

I'm currently in the midst of a corporate class on process improvement and ran into the following situation: Workflow process containing several steps. No step is skipped or done out of order. ...
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1answer
50 views

Attaining the expected value over iterations

Is my implementation of the expected value correct? I conclude that the average number of iteration of this algorithm will be 1/3, but seems completely wrong. Rand() outputs either 0 or 1 (uniform) ...
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1answer
57 views

Simultaneous Equations. [closed]

Erin goes off on a long bike ride at 10km/h. One hour later her brother starts chasing after her at 16km/h. How long will it take Alistair to catch up to Erin? Solve with simultaneous equations.
4
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2answers
42 views

Maximise difference between mean and median

I have a set of numbers and I want to maximise the difference between the mean and the median by removing a given number of elements. For instance I have the following set: ...
1
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2answers
35 views

Average $y$ from a range of $x$ in a parabola

Given a parabolic/quadratic formula such as $ax^2 + bx + c =y$, how do I get the average value of $y$ given a range of $x$ ($x_{min}$ to $x_{max}$). Real world example: if my formula represents the ...
3
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2answers
57 views

How do I properly average these percentages?

I have attendance records for an annual event: person 1: $4$ of $8$ attended $= 50.00$%, or every $2$ years person 2: $1$ of $4$ attended $= 25.00$%, or every $4$ years ...
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2answers
62 views

Calculating the average speed of a trip when given 3 different speeds for 3 percentages of distances.

The question: In a trip, $10$% of the way, Lucy drives uphill at an average speed of $56$mph; $10$% of the distance is downhill where she can manage an average speed of $72$mph. On flat ground, Lucy ...
0
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0answers
24 views

Average number of $5$-card draws before all $52$ cards in a deck are drawn.

So an interesting question was brought to me today and I'm not sure how to formulate the equation to answer it. A person draws $5$ cards from a deck, writes the cards down, puts the cards back in the ...
1
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0answers
19 views

Approximate values from point groupings

Say I am given a set of values: \begin{bmatrix}0.9&1.1&1&1.95&2&2.05&2.95&2.95&3.1&3\end{bmatrix} Is there a way I can get the 'center' or 'average' values 1, 2, ...