# Problem with linear regression

#### pavnesh

##### New Member
Dear friends,
Purpose of this Q: First of all, I am a non-mathematics/statistics student. I am doing Ph.D in botany. I have a set of data. On the first column, it is the concentration of Cadmium in soil(in lab) and 2nd column is the plant growth in cm. Since there are same multiple plants grown on the same concentration and soil, so the second set have the values of the form average±Standard Deviation.E.g. 58.82 is the av and 3.23 is SD.

1....... 58.82±3.23
10....... 62.5±7.90
50....... 87.23±2.33
100....... 110.29±10.33
200....... 84.56±8.67

I have the linear regression equation for the above data, which is y=50.2530+0.2822x and correlation coefficient (r) as 0.5858. But the problem is that I don;t know how to reach this equation and r from the above mentioned data.

Since this is an example and I have to do lot many calculations following this logic behind above eqn and r.

Any help will be highly appreciated.

~Regards
Pavnesh

#### stepha

##### New Member
You could try putting the data points in separately rather than combined into groups with a mean and standard deviation. So for example, rather than

1....... 58.82±3.23

you might have

1...54
1...58
1...62
(or whatever your results are)

Good luck. 