# Power regression Calculator

## Analyzes the data table by power regression and draws the chart.

 Power regression: y=AxB
 （input by clicking each cell in the table below） data 6digit10digit14digit18digit22digit26digit30digit34digit38digit42digit46digit50digit
 Guidelines for interpreting correlation coefficient r :　　0.7＜|r|≦1        strong correlation　　0.4＜|r|＜0.7     moderate correlation　　0.2＜|r|＜0.4     weak correlation　　0≦|r|＜0.2         no correlation$\normal\ Power\ regression\vspace{10}\\(1)\ mean:\ \bar{lnx}={\large \frac{{\small \sum}{lnx_i}}{n}},\hspace{10}\bar{lny}={\large \frac{{\small \sum}{lny_i}}{n}}\\[10](2)\ trend\ line:\ y=Ax^B,\hspace{10} B={\normal \frac{Sxy}{Sxx}},\hspace{10} A=exp{\bar{lny}-B\bar{lnx}}\\[10]\\(3)\ correlation\ coefficient:\ r=\frac{\normal S_{xy}}{\normal sqrt{S_{xx}}sqrt{S_{yy}}}\\\hspace{20}S_{xx}={\large \frac{{\small \sum}(lnx_i-\bar{lnx})^2}{n}}={\large \frac{{\small \sum} lnx_i^2}{n}}-\bar{lnx}^2\\\hspace{20}S_{yy}={\large \frac{{\small \sum}(lny_i-\bar{lny})^2}{n}}={\large \frac{{\small \sum} lny_i^2}{n}}-\bar{lny}^2\\\hspace{20}S_{xy}={\large \frac{{\small \sum}(lnx_i-\bar{lnx})(lny_i-\bar{lny})}{n}}={\large \frac{{\small \sum} lnx_i lny_i}{n}}-\bar{lnx}\bar{lny}\\$
Power regression
 [1-3] /3 Disp-Num5103050100200
[1]  2018/01/03 23:08   Female / 40 years old level / A teacher / A researcher / A little /
Purpose of use
practice finding regression models
[2]  2017/11/19 11:08   Male / 20 years old level / High-school/ University/ Grad student / Not at All /
Purpose of use
College project involving fitting curve to test data
Comment/Request
This is a nice tool, but I''m not able to use it for my project because I can''t adjust the y-axis, nor the x-axis. I''m dealing with test data where 0<= y <= 5, and 1<=x<=99. The curve being generated for my test data is entirely useless since the y-axis goes up to 1400.

I would absolutely love this if I could adjust the scale.
[3]  2017/10/18 07:54   Male / 20 years old level / High-school/ University/ Grad student / Very /
Purpose of use
more accurate A parameter than excel
Comment/Request
thank you so much!

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