Ratios

function of an angle

right|thumb|Slope: m = \frac{\Delta y}{\Delta x} = \tan(\theta)

thumb|The ratio of width to height of standard-definition television

in mathematics, two variables are proportional if a change in one is always accompanied by a change in the other, and if the changes are always related by use of a constant

parameter of elastic materials: ratio of transverse strain to axial strain

inverse function of the trigonometric function

width/height proportion of an image

sum of an (infinite) geometric progression

ratio of the density (mass per volume) of a substance to the density of a given reference material

ratio of magnetic dipole moment to total angular momentum

thumb|Points , , , and , , , are related by a projective transformation so their cross ratios, and are equal. In geometry, the cross-ratio, also called the double ratio and anharmonic ratio, is a number associated with a list of four collinear points, particularly points on a projective line. Given four points , , , on a line, their cross ratio is defined as

thermodynamic ratio of isobaric to isochoric specific heat capacities

the ratio between the number of incorrect bits transmitted to the total number of bits

In music, hemiola (also hemiolia) is the ratio 3:2. The equivalent Latin term is sesquialtera. In rhythm, hemiola refers to three beats of equal value in the time normally occupied by two beats. In pitch, hemiola refers to the interval of a perfect fifth.

measure used to characterise inelastic collisions

proportion of the working-age population who are employed

ratio of the lengths of different digits or fingers typically measured from the midpoint of bottom crease (where the finger joins the hand) to the tip of the finger

physical quantity of interest in chemistry and electrodynamics

surface slope along a stream

proportion of the sizes in different dimensions of a geometric shape

age-population ratio of those typically not in the labor force (the dependent part ages 0 to 14 and 65+) and those typically in the labor force (the productive part ages 15 to 64)

mathematical ratio relevant to climbing safety

proportion of a nuclear or particle decay going to a given decay mode

relation between the surface area and the volume of an object

ratio of total mass of a galaxy or cluster to its luminosity

aspect ratio with a width of 1.37 units and height of 1

ratio of the speed at which a wavefront passes through the medium to the speed of light in a vacuum

atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton

techniques used to compare two quantities

capacity utilization of public transport

ratio of the number of outcomes in which a specified event occurs to the total number of trials

problem-solving technique

ratio of neutrons to protons in an atomic nucleus

the ratio of the ionic radius of the cation to the ionic radius of the anion in a cation-anion compound

Measurement in oil production

measure of the efficiency of a rocket based on its propellant's mass

The ratio between the amount of carbon dioxide produced in metabolism and oxygen used