Consider the following table, consisting of 20 observations of the

Consider the following table, consisting of 20 observations of the variable y and time t.

Consider the following table, consisting of 20 observations of the

a. Plot the series along with the superimposed linear and quadratic trends. Which trend model do you think describes the data well?
b. Estimate a linear trend model and a quadratic trend model. Validate your guess from the graphs by comparing their adjusted R2.