Applied to focusing lenses and mirrors, including telescopes, binoculars, and cameras, the focal ratio or 'F-number' is
(the focal length of the lens or mirror) divided by (its aperture or diameter)
f-ratio is a fraction of total primary production fuelled by nitrate
positively skewed with all values greater than or equal to zero
The F-ratio is used to determine whether the variances in two independent samples are equal. If the F-ratio is not statistically significant, you may assume there is homogeneity of variance and...
No. There is no platinum ratio.
ratios are maths way of say there are eg: 3 boys for 15 so there would be 18 people in the class