A data set is used to find the regression line that relates the length and weigh
ID: 3073405 • Letter: A
Question
A data set is used to find the regression line that relates the length and weight of a particular animal. Then it is used to predict the weight of the animal that is 270 cm long; which is found to be 168 kg. In looking back at the data, you notice that an animal in the sample was 270 cm long but weighed 170 kg. What explains the difference in your prediction and your observation? Select one: a. The predicted weight is clearly wrong. Most likely an error was made in the calculations. b. Neither value is wrong. A difference between the observed and predicted weights is expected. It is called the residual of the regression. c. The observation is clearly wrong. Most likely an error was made in recording the animal's true weight. d. Neither value is wrong. It is just a case of rounding error.
Explanation / Answer
b. Neither value is wrong. A difference between the observed and predicted weights is expected. It is called the residual of the regression.
The difference between the observed value of the dependent variable (y) and the predicted value () is called the residual (e).