Similarly, if p, q, r and s are in proportion then q and r are called two mean proportionals to p and s. Definitions 9 and 10 apply this, saying that if p, q and r are in proportion then p:r is the duplicate ratio of p:q and if p, q, r and s are in proportion then p:s is the triplicate ratio of p:q.
You might use a ratio to compare the number of boys in a room to the number of girls in a room, or the number of students who had pizza for lunch versus the number of students who didn't have pizza for lunch.
They will encounter many forms of numerical comparisons in the media. The first, part-to-whole, compares the quantity of one type of objects to a larger group, such as the comparison of the number of apples to all the pieces of fruit.
So you'd describe either of the ratios just given as the ratio of students who did pass to the students who didn't pass. Though it may not be possible to assign a rational value to a ratio, it is possible to compare a ratio with a rational number.
We could also write it using the word "to," as "3 to 6. The fraction of the group that is male is. References Purple Math: Ratios About the Author Lisa studied mathematics at the University of Alaska, Anchorage, and spent several years tutoring high school and university students through scary -- but fun!
Early translators rendered this into Latin as ratio "reason"; as in the word "rational". Converting Ratios Into Percentages When you want to turn a ratio into a percentage, you must choose just one part to compare against the whole. The reasons for this are twofold.
Be sure you understand that these are all ways to write the same number. Some other equal ratios: Are and equal ratios?