i am given data for analysis following data:relationship between height and weight,question is :is relationship between them linear?like $y$=$a$+$b$*$x$+$e$ where e is error,or quadratic?or cubic?data is following(y denoted height, x-weight)
y x
170 65
167 55
189 85
175 70
166 55
174 55
169 69
170 58
184 74
161 56
170 75
182 68
167 51
187 85
178 62
173 60
172 68
178 55
175 65
176 70
i have calculated a and b and get following result
y=139.6155237+0.5308912572*x
i dont know how to calculate e?or what me result means?please help me how to find e and how to check correctness of my work
EDITED:
i have edited my work,i am sure it is correct,what now should i do?
First you fit the data with your expectation model: $y=a+bx$
Then you compute pertuberations of data points around the model curve (line). Analysis of this will give you variance in data points (the error). The least squares approach expects the errors are distributed normally, so that the errors should be samples drawn from gaussian distribution.
Your (least squares) estimator have two properties: precision and accuracy. I think the precision is what you want to compute. Accuracy is about bias, and this is harder to grasp (e.g. all weights are slighly bigger because of uncalibrated measurement device).