Talk:Rate (mathematics)

message: Want to help write or improve articles about Time? Join WikiProject Time or visit the Time Portal for a list of articles that need improving.
—Yamara ✉ 23:10, 5 May 2008 (UTC)
thread_title:  [[Wikipedia:WikiProject_Time/Assessment|WikiProject Time assessment rating]] comment 

message: hello i want to see a table of reactivity --193.195.198.254
You should ask for this on Talk:Reactivity. --Toby Bartels 15:35, 2 March 2007 (UTC)
thread_title: Discussion

message: I do not see that 'meters' and 'seconds' are the same unit, what would in fact be a 'ratio'. That definition differs completely from that e.g. in the Oxford Dictionary.HJJHolm (talk) 13:43, 15 July 2008 (UTC)
replies: text: Your point regarding that the two measurements is taken. They can be the same unit or different units.+mt 14:33, 15 July 2008 (UTC)
thread_title: Definition

message: Rate is a measure of something over time.  And the article should say that.  Re-write.  Paul Beardsell (talk) 07:23, 1 March 2009 (UTC)
replies: text: Your claim is incorrect. A rate is simply a ratio of something per something used in a particular context. The denominator is often time, but it doesn't need to be. Examples of rates that are not "something over time" include exchange rate, inflation rate, unemployment rate. +mt 17:59, 1 March 2009 (UTC)

text: We agree that this is a mathematics article, but variables and dimensions are usually treated generically in math, so this doesn't help your case. My calculus textbook () has all sorts of examples that describe rates that are not "per time", such as "the rate of change of the area of a circle with respect to the radius" in one example or "the rate of change in gravitational force with respect to distance from Earth", etc. Yes, this book also provides many "per time" examples as well. Search for "rate" in derivative and evaluate the context in which it is used. The formal definition of the "rate of change" in my textbook (p.129), (added to front page) does not assume "per time" anywhere since it is an unnecessary limitation. In an applied use, a gradient rarely has rates in units "per time" (usually it is a spatial dimension). Still not convinced? Look for the definition of "rate" at these links: , , , , . I'm all for improvements in this article and I'll agree that the prior version was mismanaged, but you completely modified the definition to what you thought it was, which is why I revered your work (also, consider the use of a spell-checker). The content of your edits are not wrong, but your assumption of always "per time" is not correct and is not supported by references. Terms like "unemployment rate", "tax rate", "exchange rate" are not wrong, since this terminology sits fine with the formal definition that I'm showing you. +mt 05:41, 2 March 2009 (UTC)
replies: text: You're right.  Sorry to be disruptive.  But the default "per unit" is "per unit time".  If you don't say then the rate of something is the rate per unit time.  Notice also the project template (how I hate those).  Paul Beardsell (talk) 08:27, 2 March 2009 (UTC)
replies: text:  I'm not convinced that the default should be "per unit time".  All percentages are rates and they are mostly not per unit time.  For example, the percentage of people divorced is the ratio of divorced people to total population.   It's better not to think of it as a rate since the "divorce rate" means the percent of marriages that end in divorce.  This is a rate that is not "per unit time".  — Preceding unsigned comment added by Dlawyer (talk • contribs) 03:15, 24 November 2015 (UTC)

text:  I've thought about this some more and I think that in Physics "per unit time" should be the default.  But now I'm proposing a new title for this article that will resolve this problem: "Rates and ratios (mathematics)"David S. Lawyer 01:40, 25 November 2015 (UTC)
thread_title:  Is Rate is all about time ?

message: This would solve the argument as to whether a certain ratio is a rate.   For example, I'm not sure if the percent of the population that is under 16 is really a rate, but it most definitely is a ratio.  Then create a lot of redirects to this new name: ratio, ratios, rate, rates (math), etc.David S. Lawyer 00:18, 25 November 2015 (UTC)
thread_title: Proposed name change: Rates and ratios (mathematics)

message: The sentence in the first paragraph of the section that begins "For example" contains the word "tracity", not in any dictionary I've checked. It has more left parentheses than right parentheses. It mentions a subset of a route, but only sets have subsets; since when is a route a set?
The third paragraph refers to "a set of ratios (i=0,N)". In this set, is N supposed to range over the positive integers, so that (0,2) is a member of the set? According to the lead in the Ratio article, ordered pairs can be ratios.  Does the set then consist of ratios like 0∶2, 0∶3, etc.? The paragraph also refers to "the set of vis mentioned above" though no vis have been mentioned. The first paragraph, if I guess correctly concerning its parentheses, says that v is a function of i, so maybe the reference should be to the values of v(i) rather than to the vis?  Either way, what are these values? We're told that the i's can be assigned to political subdivisions so, OK, I hereby assign 43 to Idaho since it was the 43rd state to join the United States. Now, what is v(43) or v43?
Peter Brown (talk) 01:16, 3 November 2019 (UTC)
thread_title:  Can anyone make sense of the 1st and 3rd paragraphs  in the [[Rate_(mathematics)#Introduction|Introduction]] section? 

message: These are some basic questions about rates that must be answered.
I believe that "per" means a rate. I believe percentages are rates constructed out of 100 unites.
All rates must have two and only two variables as an equation must have two sides. There are two types of rates. One type is constructed out of dependent variables and the other type is constructed out of independent variables.
If I say 10% am I saying "10 parts per 100 parts" or "10 parts of 100 parts"?
This is a most important question for an understanding of the distinction between "of" and "per" is essential.
Is 10 parts per 90 parts equal to 100 parts? Is 10 parts per 100 parts equal to 110 parts?
Rates constructed out of dependent variables have a commonality of units.
When I say parts I of course am talking about common unites.
Can one average percentages? Can one average rates?
If one has a container with 10% alcohol in it and mixes a container with 50% alcohol in it can one know the percentage of alcohol in the mixed container? 
The answer to this is true for all rates and percentages are rates.
If I am wrong please correct me.
Mwdar (talk) 18:46, 3 January 2020 (UTC)
thread_title:  Rates and what they are