What is Average: Definition and 1000 Discussions

In colloquial language, an average is a single number taken as representative of a non-empty list of numbers. Different concepts of average are used in different contexts. Often "average" refers to the arithmetic mean, the sum of the numbers divided by how many numbers are being averaged. In statistics, mean, median, and mode are all known as measures of central tendency, and in colloquial usage any of these might be called an average value.

View More On Wikipedia.org
Recent contents Top users
  1. X

    Average Dose Rate of 1.11x108 Bq 131I in Thyroid

    Homework Statement A patient receives an injection of 1.11×108 Bq of 131I,30% of which goes to the thyroid, having a mass of 20 g.What is the average dose rate in the organ? Homework Equations D=1.60×10–10AE Gy s–1 The Attempt at a SolutionA=(1.11x108x(30/100))/20=1.665x106Bqg-1 E=0.192Mev...
  2. X

    Average Dose Rate for 1.11x108 Bq of 131I Injection

    A patient receives an injection of 1.11×108 Bq of 131I,30% of which goes to the thyroid, having a mass of 20 g.What is the average dose rate in the organ? Solution: D=1.60×10–10AE Gy s–1 A=(1.11x108x(30/100))/20=1.665x106Bqg-1 E=0.192Mev =1.60x10-10 (1.665)(0.192Mev) = 51μGy s–1 This is...
  3. I

    What is the average of fall distances

    [no template, as this post was moved from here from the Quantum Mechanics forum] In griffiths 2nd quantum mechnics, problem : Suppose I drop a rock off a cliff of height h. As if falls, I snap a million photographs, at random intervals. On each picture I measure the distance the rock has...
  4. caffeinemachine

    MHB Finding an Infinite Binary Sequence with Average Frequency of 1's = p

    The following question came up when me and a friend of mine were discussing some basic things about probability:Let $p$ be a real number in $[0,1]$. Does there exist a sequence $(x_1, x_2, x_3, \ldots)$ with each $x_i$ being either $0$ or $1$, such that $$ \lim_{n\to \infty} \frac{f(n)}{n} =p...
  5. L

    The average density of halo of non-baryonic dark matter?

    I've got a homework question that I'm particularly stuck on: Suppose that the halo, assumed spherical, of non-baryonic dark matter surrounding our galaxy has mass ~ 5 x10^12 M solar and radius 0.1 Mpc. What it its average density in Kg m-3? I think that I need to use the formula...
  6. B

    How to find average current of trapezium

    Can anyone teach me how to find the average current of Trapezium? i have attached the pic
  7. B

    RMS and average current triangle

    I would like to know how to find RMS and average current of a triangle? i searched the web. but it focus from 0. which i know. but my waveform is different from the internet. i have attached the waveform.. Maximum = 2.5 , Minimum = 1.8 i need to find out the RMS and average current
  8. Z

    MHB Average Problem [Need Formula]

    hi all.. how to make formula for problem below : The average math test scores of 36 students is 86. There are four students attend subsequent replications and obtain an average value of 80. Find the average value of all the students! can you make simple? zidan3311
  9. P

    Find the average height of a pyramid

    Homework Statement Homework Equations V = (1/3) * A * H [Volume of Pyramid] The Attempt at a Solution The first thing I did was to calculate the height of pyramid from the volume formula. I got a perpendicular height of 15. I'm not sure where to go from there. I'm under the impression...
  10. H

    Finding collected count when given average value.

    Good morning everyone, I would really be pleased with a quick answer because I am very soon going to school. I have been asked to plot a graph, for that I am given a table with time in minutes from 0 to 6 on the first row. On the second row I was given activity in counts per minute with values...
  11. Damian Norton

    Programs How many hours, on average, of pure learning for bachelor degree?

    Hello. I am in desperate need for advice. I have searched for advice everywhere and each time failed to obtain it. This is my last resort. Please help me and bare with me while I explain the problem. I am 28 years old guy. I have literally whole day free to pursue whatever goals I see fit...
  12. S

    What is the average intensity at a distance?

    Homework Statement A 60 W bulb radiates light uniformly in all directions. What is the average intensity of the light bulb at a distance 0.40 m. Homework Equations I = P/A, part of my problem is that I don't know the relevant equations The Attempt at a Solution
  13. Lesliedenise57

    What is the magnitude of the average velocity v of the car?

    Homework Statement A car is traveling a road that makes quarter of a circle with a constant speed s. What is the magnitude of the average velocity v of the car? Homework EquationsThe Attempt at a Solution this is what I have down but I am not sure if I am right *constant speed formula...
  14. Poetria

    How Is Average Velocity Calculated in Circular Motion?

    Homework Statement A bicyclist makes a three quarter turn of radius 1.5 m at constant speed. During the turn, the only horizontal force acting on the bicyclist is a static friction force of constant magnitude 250 N. The total mass of the bicycle and rider is 60 kg.Homework EquationsThe Attempt...
  15. J

    The standard of living is going down for the average American

    average American. The economic pie just isn't growing at a fast enough rate to keep up with the population growth. It's interesting how, when it comes to the big costs in life -- housing, health care, education -- everyone is paying more and getting less, yet no one seems to realize this. As...
  16. J

    Calculating standard deviation for average force

    Homework Statement I am stuck on the last problem. Homework Equations Just the error propagation equations The Attempt at a Solution I initially used the multiplication error propagation formula. So the average force would be the impulse divided by the time, the same thing as the impulse...
  17. P

    Average velocity in uniform circular motion

    Suppose a particle undergoing uniform circular motion completes a cycle, then ##<\vec{v}> = \frac{Δ\vec{r}}{Δt} = \vec{0}##. But then again, isn't it also the mean of the two velocity vectors at that point? And aren't those two velocity vectors equal? So if the velocity at that point were, say...
  18. K

    Finding average angle in kinetic theory of gases

    Homework Statement "Show that particles hitting a plane boundary have traveled a distance 2λ/3 perpendicular to the plane since their last collision, on average."Homework Equations (Root mean path squared) <x> = 2^(.5)λ λ = ( 2^(.5) * n * sigma )^(-1) ANSWER: The Attempt at a Solution...
  19. E

    What is the Average Speed of an Object Traveling 12 Meters in 9 Seconds?

    1. I'm a middle school science teacher without a science or math background. My goal here is to avoid teaching an explanation that kids will have to unlearn later in their academic career. I'm designing a lesson to teach students how to answer this question: 2. Limitation: students are NOT...
  20. H

    Methods for calculating average velocity

    Homework Statement A child is pushing a merry-go-round. The angle through which the merry-go-round has turned varies with time according to θ(t)=γt+βt3, where γ= 0.383 rad/s and β= 1.00×10−2rad/s3. Calculate the average angular velocity ωav−z for the time interval t=0 to t= 5.50s. Homework...
  21. M

    Determining average acceleration during point of impact

    Homework Statement Hello, new to the physics world, I am trying to self-teach through reading textbooks, videos etc and application. I came across a problem I do not know how to begin to answer. A dodgem car of mass 200g is driven due south into a rigid barrier at an initial speed of 5.0...
  22. Sarlacc

    Average Speed Over Given Distance - Driving me Nuts

    "A car accelerates from rest over 400 metres in 19 seconds. The driver then brakes and the car stops in 5.1 seconds with constant deceleration." Part one of the question is "calculate the acceleration for the first 400m" which went just fine: x=ut+(1/2)at^2 400=180.5a a=2.22 m/s Now the...
  23. D

    Back EMF in Average Loudspeaker Coil: Compare to 18V

    Homework Statement The coil in a loudspeaker has an inductance of L = 56uH (or 5.6 x 10^-5 H). To produce a sound frequency of 20 kHz, the current must oscillate between peak values of +2.2 A and -2.2 A in one half of a period. What average back emf is induced in the coil during this variation...
  24. E

    Quantum harmonic oscillator: average number of energy levels

    Homework Statement I must find the average number of energy levels of quantum harmonic oscillator at temperature T, and the answer is given as I must use Boltzmann distribution and the sum of geometric progression. For finding the average value I must use the equation <F>=trace(F*rho)...
  25. Z

    What is the average force on the wall?

    Homework Statement A ball hits the wall in a normal direction with v=10m/s. After the hit which lasted 0.2 Seconds, it turned in the same direction with v=10m/S. Knowing that its mass is 0.5 kg, find the average force that hit the wall. Homework Equations F=m*a, a= (v-v0)/t The Attempt at a...
  26. Poetria

    The average velocity of the point - numerical value of t

    Homework Statement During the first t seconds of motion, the average velocity of the point is zero. What is the numerical value of t? Homework EquationsThe Attempt at a Solution I don't understand this question. I understand that the average velocity is zero if the displacement in the...
  27. B

    Neon Atom Speed Ratio at Different Temperatures

    Homework Statement What is the ratio of the average speed of an atom of neon to another atom of neon at twice the temperature? (A) 1:1 (B) 1:1.4 (C) 1:2 (D) 1:4 Homework Equations KE = 3/2RT The Attempt at a Solution I used the above equation and substituted 2 for T for twice the temperature...
  28. G

    Average percent growth per year

    Homework Statement If a stock has increased 400% over the last 6 years, then how much does it grow on average per year. Homework Equations 400 = 100(1+r/6)^6 The Attempt at a Solution Divide both sides by 100 4 = (1+(r/6)^6 Take the sixth root of each side. 1.26 = 1 + (r/6) Subtract...
  29. H

    Calculating Work by Friction using Integrals

    Homework Statement A uniform board of length L and mass M lies near a boundary that separates two regions. In region 1, the coefficient of kinetic friction between the board and the surface is μ1, and in region 2, the coefficient is μ2. The positive direction is shown in the figure. Find the...
  30. Q

    The average power consumed -- where is my mistake

    Homework Statement We have the circuit in the figure.I have to find the average power consumed by all the elements and the source. Homework Equations P=0.5*(I^2)*R P=-VmImcosθ/2 The Attempt at a Solution The inductor consumes zero inductive power. I apply nodal analysis at node Vo We have...
  31. T

    What Is the Average Angular Speed of a Race Car on a Circular Track?

    Homework Statement A race car makes two laps around a circular track in 3.8 minutes. What is car's average angular speed?
  32. N

    The time average potential of neutral hydrogen atom

    Homework Statement [/B] The time-averaged potential of a neutral hydrogen atom is given by where q is the magnitude of the electronic charge, and being the Bohr radius. Find the distribution of charge( both continuous and discrete) that will give this potential and interpret your result...
  33. IDespisePhysics

    Finding average horizontal force?

    Homework Statement A car is traveling at 60.0mph when it collides with a stonewall. The car comes to rest after the first foot of the car is crushed. What was the average horizontal force acting on a 150lb driver while the car came to rest? Homework Equations I'm not a hundred percent sure...
  34. R

    Average speed? -- Homework problem

    Ok let me just type the question and get to the real question I have. If you traveled one mile at a speed of 100 miles per hour and another mile at a speed of 1 mile per hour, your average speed would not be (100 mph+ 1 mph)/2 or 50.5 mph. What would be your average speed? (Hint:what is the...
  35. M

    Momentum/Impulse- Calculating Average Force of Raindrops

    Homework Statement The problem says: "A record rainstorm produced 304.8 mm (approximately 1 ft) of rain in 42 min. Estimate the average force that the rain exerted on the roof of a house that measures 10 m * 16 m. Indicate any assumptions you made. (Note: density of water is 1000 kg/m3"...
  36. diemilio

    Calculating Average Power for Sinusoidal Acceleration with an Accelerometer

    Hello, I have a system of mass m that has an accelerometer strapped to it. The accelerometer is measuring a sinusoidal acceleration with peak amplitude of amax: https://www.dropbox.com/s/y49pcrhqbrzk27t/Accel_System.png How can I calculate the average power (in Watts) that is being delivered...
  37. G

    Is F in P=F/A an average or a sum of all microscopic forces?

    Hello, I've read that the force F we use in the pressure formula P=F/A is an average of all microscopic forces exerted by the gas on the wall of the container over a period of time. Is it true? I thought it was a SUM rather than an average? I assume that in that definition the microscopic force...
  38. ranju

    What is the optimal range for calculating the average value of a wave?

    Homework Statement In the given fig. we have to find average value of the voltage wave . So , for that we should take limits from 0 to pi/2.! But in solution it is taken as pi/2 to 3pi/2..! I did'nt get this..why so?[/B]Homework Equations average value of voltage = 1/pi limit integral...
  39. K

    Find the average force of friction

    Homework Statement A 5kg box is tossed across the floor at 4 m/s and slides to a stop in 3 seconds. What is the average force of friction? Homework Equations I believe the answer is 6.66N, I found that because the problem was pulled from the book. But I am trying to understand how and why...
  40. P

    Can Distance Traveled be Calculated Mathematically in Average Speed?

    It is my understanding that while instantaneous speed is the magnitude of instantaneous velocity, average speed is , in general, not the magnitude of average velocity, since average speed is total distance traveled divided by change in time. Why is the mathematical definition of average speed as...
  41. G

    What is the average force required to pull the rope?

    Homework Statement Problem 3.12 from Kleppner & Kolenkow A ski tow consists of a long belt of rope around two pulleys, one at the bottom of a slope and the other at the top. The pulleys are driven by a husky electric motor so that the rope moves at a steady speed of 1.5 m/s. The pulleys are...
  42. P

    Ultra-relativistic gas average energy as E(T)

    Homework Statement Ultra-relativistic particle with energy epsilon and momentum p is described by epsilon=cp. Find average energy E(T) of gas which consists of particles described above. Homework Equations So i think i should use this kind of equations(please use the link below)...
  43. T

    Calculating Weighted Averages in a Course

    the question statement is2. In a course, a student's final exam is weighted twice as heavily as his midterm exam. If a student receives a score of 84 on his final exam , 90 on his midterm, what is the average for his courses? now i am pretty confused should I have to know the total marks for...
  44. P

    Surface tension vs Average Bond Strength

    If you increase the surface tension of a liquid, does it change the average bond strength of the liquid?
  45. E

    How to Calculate Average Velocity with Displacement & Speed?

    Homework Statement A car travels 14.6 km west at a speed of 40 km/h, then travels 12.0 km south at a speed of 50 km/h and finally travels 19.0 km east at a speed of 45 km/h. What is the magnitude of the average velocity for the car over the entire trip? Homework Equations 3 kinematics...
  46. Rugile

    Average power in series LC circuit

    Homework Statement A voltage source is connected to a series LC circuit. The frequency of the source is resonant. The voltage amplitude of capacitor is 1V. Find the average power in the circuit. Homework EquationsThe Attempt at a Solution I realize that if there is no active resistance the...
  47. Kevin Le

    Average distance among pieces of space debris in low earth orbit?

    Hello all, I have a question about space debris. The number of space debris in the low Earth orbit is huge.There are more than 170 million pieces of space debris which is greater than 1mm. So in the orbit of the Earth, what is the average distance between 2 pieces of space debris?
  48. E

    MHB Determine the Average Rate of Change

    Determine the average rate if change of the function y = 2cos(x - $\pi$/3) + 1 for the interval $\pi$/3 $\le$ x $\le$ $\pi$/2 I tried finding the exact values of the two (0 and 0.5) and subbing them into the AROC equation but I keep getting the wrong answer (1.4)
  49. R

    Average force between baseball and bat

    Homework Statement [/B] A 0.145- kg baseball with an initial speed of 20 m/s rebounds with a speed of 36 m/s after being struck with a bat. If the duration of contact between ball and bat was 2.4 ms, what was the magnitude of the average force between ball and bat? Homework Equations Δ...
  50. B

    Average force on a baseball when struck by a bat

    Homework Statement Baseball(0.145kg) pitch is pitched horizontally at 32m/s, ball pops straight up to a height of 36.5m. If the contact time between bat and ball is 2.5ms, calculate the average force between the ball and the batt during contact. Homework Equations Favg = Δp/t KE=KE The...
Back
Top