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# Math and Science Solutions for Businesses/using excel for a specific function

Question
If I have two specific non-changing numbers and a total amount but don't know how the two numbers came to get that total (I don't know the equation that was used to get the total) is there a formula in excel that will provide me with the equation?  Or some other spreadsheet perhaps that will provide me with the proper equation used between the two numbers to get the specific total?

JoDee,

The short answer is no, but there may be hope. It sounds like the situation can be described as

f(x,y) = z

where x, y and z are known but f isn't. The function f could be a lot of things (e.g., z = x^2/y). The easiest form for f would be something like

ax + bx = z

where and and b need to be specified (they don't have to be integers). This can be done if any other information is available that relates any of x to y, x to z or y to z. Perhaps if you could tell me the context of your problem we could figure something out. There isn't a "magic" function in Excel to back out f.

Randy
Questioner's Rating
 Rating(1-10) Knowledgeability = 10 Clarity of Response = 10 Politeness = 10 Comment Great response! Not what I had hoped for but what I expected none the less! :)

Math and Science Solutions for Businesses

Volunteer

#### Randy Patton

##### Expertise

Questions regarding application of mathematical techniques and knowledge of physics and engineering principles to product and services design, optimization, prediction, feasibility and implementation. Examples include sales and product performance projections based on math/physics models in addition to standard regression; practical and cost effective sensor design and component configuration; optimal resource allocation using common tools (eg., MS Office); advanced data analysis techniques and implementation; simulation and "what if" analysis; and innovative applications of remote sensing.

##### Experience

26 years as professional physical scientist and project manager for elite research company providing academic quality basic and applied research for government and defense industry clients (currently retired). Projects I have been involved in include: - Notional sensor performance predictions for detecting underwater phenomena - Designing and testing guidance algorithms for multi-component system - Statistical analysis of ship tracking data and development of anomaly detector - Deployed vibration sensors in Arctic ice floes; analysis of data - Developed and tested ocean optical instrument to measure particles - Field testing of protoype sonar system - Analysis of synthetic aperture radar system data for ocean surface measurements - Redesigned dust shelters for greeters at Burning Man Festival Project management with responsibility for allocation and monitoriing of staff and equipment resources.

Publications
“A Numerical Model for Low-Frequency Equatorial Dynamics” (with Mark A. Cane), J. of Phys. Oceanogr., 14, No. 12, pp. 18531863, December 1984.

Education/Credentials
MIT, MS Physical Oceanography, 1981 UC Berkeley, BS Applied Math, 1976

Past/Present Clients
Am also an Expert in Advanced Math and Oceanography