Questions from Business Statistics

Q: a. What fraction of the variation in salaries can be explained

a. What fraction of the variation in salaries can be explained by the fact that some employees have more experience than others? b. What salary would you expect for an individual with 8 years of exper...

Q: a. If large values of X cause the Y values to

a. If large values of X cause the Y values to be large, would you expect the correlation to be positive, negative, or zero? Why? b. If you find a strong positive correlation, does this prove that larg...

Q: a. What is so special about the least-squares line

a. What is so special about the least-squares line that distinguishes it from all other lines? b. How does the least-squares line “know” that it is predicting Y from X instead of the other way around?...

Q: Define the predicted value and the residual for a given data point

Define the predicted value and the residual for a given data point.

Q: For multiple regression, answer the following: a. What

For multiple regression, answer the following: a. What are the three goals? b. What kinds of data are necessary?

Q: a. What are the axes in the diagnostic plot?

a. What are the axes in the diagnostic plot? b. Why is it good to find no structure in the diagnostic plot?

Q: a. What is an elasticity? b. Under what

a. What is an elasticity? b. Under what circumstances will a regression coefficient indicate the elasticity of Y with respect to Xi?

Q: How does polynomial regression help you deal with nonlinearity?

How does polynomial regression help you deal with nonlinearity?

Q: a. What is interaction? b. What can be

a. What is interaction? b. What can be done to include interaction terms in the regression equation?

Q: a. What kind of variable should you create in order to

a. What kind of variable should you create in order to include information about a categorical variable among your X variables? Please give the name of the variables and indicate how they are created....