Ratios Definition and 224 Threads

In mathematics, a ratio indicates how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8∶6, which is equivalent to the ratio 4∶3). Similarly, the ratio of lemons to oranges is 6∶8 (or 3∶4) and the ratio of oranges to the total amount of fruit is 8∶14 (or 4∶7).
The numbers in a ratio may be quantities of any kind, such as counts of people or objects, or such as measurements of lengths, weights, time, etc. In most contexts, both numbers are restricted to be positive.
A ratio may be specified either by giving both constituting numbers, written as "a to b" or "a∶b", or by giving just the value of their quotient a/b. Equal quotients correspond to equal ratios.
Consequently, a ratio may be considered as an ordered pair of numbers, a fraction with the first number in the numerator and the second in the denominator, or as the value denoted by this fraction. Ratios of counts, given by (non-zero) natural numbers, are rational numbers, and may sometimes be natural numbers. When two quantities are measured with the same unit, as is often the case, their ratio is a dimensionless number. A quotient of two quantities that are measured with different units is called a rate.

View More On Wikipedia.org
Recent contents Top users
  1. 5

    Comparing Rod Ratios: Pressure on Pistons & Cylinder Walls

    Well I am getting into how engines work and am trying to learn. I was wondering if there is a formula I can follow to find out how much more pressure is applied on the piston end towards the cylinder walls if the rod ratio is steeper. I want to compare a 1.59 Rod Ratio (347 cubic inch) to...
  2. J

    Characteristic X-rays, intensity ratios

    Hi! What can be said about the intensity ratios of characteristic X-rays (Kalpha to Kbeta ) originating from a X-ray tube? I mean roughly and in general, not for some very specific anode material. I first thought that K-L (Kalpha) transitions would be more likely to happen than K-M:s...
  3. M

    Calculating Partial Transition Rates W from Branching Ratios

    How do I calculate partial transition rates W if I know the Branching Ratios of the different modes? :confused:
  4. M

    Amedeo Avogadro & Molar Ratios: Gases, Solids & Solutions

    Can I use molar ratios for gasses, solids, and aqueous solutions all in one equation? For instance: Mg(s) + 2 HCL(aq) -> MgCl2(aq) + H2(g) Can I say that if i had 2 moles of Mg I would have 2 moles of H2. Does this trick have anything to do with Amedeo Avogadro?
  5. samalkhaiat

    Explaining E/M Ratios of Charged Particles without Math

    According to GR as well as Maxwell's theory, when charged particles are accelerated they radiate energy by electromagnetic and gravitational radiation. This energy, according to special relativity, is equivalent to mass. I wonder, how can elementary particles preserve their fixed e/m ratios...
  6. J

    Testing Phenotypic Ratios: Results of Chi Square Test

    Hi, My Question: Problem 1. The expected phenotypic ratios for each of the crosses below is 1:1. Determine whether the observed ratios are differ significantly (p < 0.05) from the expected. I used a Chi Square test to help me determine that answer and found the there is no probability of...
  7. T

    Help with Ratios: Splitting 500 bucks

    Hi! I have a supposedly simple question. Two people are splitting 500 bucks between them. First it will be split in a 3/5 ratio. Wouldn't the answer just be that one them gets 200 and the other gets 300? I think so. So, following this last thought, if it is to be split in a 2/3 ratio...
  8. W

    Calculating Gear Ratios - Need Assistance?

    Hi , is anyone studying gear ratios?? i need some help with calculating the final gear drive.. i've calculated it at 94.97:1 is this correct??
  9. T

    Simple ratios dilemma; telescopes and signals from out of space

    Hi, Here's the question: a) There is a radio telescope that is 1000 feet in diameter. It is claimed that it can detect a signal that lays down on the entire surface of the Earth a power of only one picowatt. What power would be incident on the antenna in this case? It seems to me that...
  10. S

    Mass Ratios and Mutiple Proportions

    The "Law of Multiple proportions" states that if two elements combine in different ways to form different substances, the mass ratios are small, whole number multiples of each other. Suppose that you have 66g of carbon combined with oxygen in carbon dioxide (CO2), how many grams of oxygen would...
  11. M

    Ratios of work to height with same mass

    This is a question from the MCAT, test 3R, and I am stumped as to why the answer is what it is. "A mass is lifted from the ground to an altitude h1, requiring work W1. The work to lift an identical mass to height h2 is W2. If h2 is twice h1, what is the ratio of W2 to W1? Assume force due...
  12. E

    Finding Ratios to Solving Problems

    I've been trying to get the ratio of the french minute of 100 seconds and the standard minute 60 seconds. The textbook gives me answer of 0.084 and I can mess with these numbers and eventually change 60 to 100 or vise versa. I tried google but they only do 1:4 type of ratios and the textbook...
  13. I

    Gear Ratios: what happens to the force?

    Ok here's a fairly simple question (I hope) i know that with different gear ratios you can trade off torque for speed, (ie. big to small = lower torque higher speed, small to big = higher torque lower speed) but what happens to the force applied to the original gear? is it a constant throughout...
  14. J

    Calculating Ratios of Moments: Spatial Extent of Distribution

    I've been told that there are useful interpretations of the ratios of moments of probability density distributions, such as <x^4>/<x^2>. I only have un-normalised values of the second and higher moments of the distribution of interest. Is there any way of quantifying the spatial extent of the...
  15. T

    Trigonometeric Ratios: Tire Speed

    Can someone get me started? This is a homework question that I just can't get started on. No wonder it's a "challenge" question. A car is traveling at 100km/hr. A) What is the angular speed of a tire which has a radius of 36cm. B) Through how many radians will the tire turn in 30s at...
  16. R

    Pythagoras' Perfect Ratios: Uncovering the Base 10 Anomaly

    Base 10 Anomaly An applied 49-year study into the origin of pi and the Base 10 number system resulted in the finding of a highly anomalous formula. Essentially, the finding derives from the perfect ratios (0:1:1:2:3:4) given by Pythagoras who we know studied and perhaps taught in the...
  17. V

    How Do I Calculate Temperature and Pressure Ratios in an Adiabatic Engine Cycle?

    This one had three bullets by it so it's a pretty tough one. Work and rambling thoughts so far... please tell me if I'm wrong. This would be a change in entropy problem for the first couple of ratios right? (delta)S=Sfinal-Sinitial=nRln(Vf/Vi)+nCvln(Tf/Ti) yet it is an adiabatic operation...
  18. V

    Why Don't Surface Area & Volume Ratios of Spheres Match?

    Howcome the ratio of the surface area of spheres are not equal to the ratio of volume of spheres? For example if I had two spheres, with an aspect ratio of 1:4 when comparing surface areas, yet I have 1:8 between those same spheres when comparing volume. This doesn't make sense to me...
  19. G

    Understanding the Mass Ratios of Electrons and Neutrons in Atoms

    Is there any reason why an electron is 1084(I think that's right) times smaller than the mass of a neutron. is there any mathematical or "physical" reason why this works for atoms and if so what would be the consequences of a proton having half that mass but with the same ratio to an electron or...
  20. N

    Calculating Electric Field Ratios for H+ and K+ Ions

    The ratio of electric fields, E1/E2, at the surfaces of ions when H+ is the first ion (q=+1 and R=0.00001 Angstrom) and K+ is the second ion (Q=+1 and R=1.33 Angstrom) is: how would u solve this kind of problem? well i know that the ratio of E1/E2 is qR^2/Qr^2 so do i just plug in those...
  21. B

    16:9, 16:10, 4:3, 1.85:1, 2.35:1, 1:66:1, 5:4 aspect ratios.

    All you tech geeks out there, aren't you sick and tired of all the different aspect ratios for viewing images and movies? I for one am. They adopted the 4:3 standard when film was first invented. They used it for TVs and movies. They used this ratio for decades. Then someone came along and...
  22. W

    Help with ratios of velocity and centripetal acceleration

    I really need some help with this question. Until now this is the first question I have ever seen like this and I am getting marked on it. here it is: Two racing cars of masses M1 and M2 are moving in circles of radii R1 and R2. Their speeds are such that they each make a complete circle in...
  23. shintashi

    How Do Wave Properties Relate to Mass and Energy?

    “wave radius” used for spherical wave patterns, same as wave length. “Wave density” same as wave frequency. Gamma wave 1e-11 wavelength multiplied by 3e19 frequency rquals total mass Total “energy” of gamma wave = 2e-14 Radio wave length 1e-1, multiplied by 3e9 frequency equals total...
  24. M

    Comparing Forum Post/Thread Ratios

    okay, i was a little bored so i computed the current thread to post ration for all the forums above this one. the one with the highest ration is Philosophy, averaging out at aprox. 33.24 posts per thread! (that's including religion as a subforum) and in last place we have Mathamatics...
Back
Top