Question

Solve the following problem in R and print out the commands and outputs.

3. The data set fancy (you need to library the fpp package to get the dataset) concern the monthly sales figures of a shop which opened in January 1987 and sells gifts, souvenirs, and novelties. The sales volume varies with the seasonal population of tourists.

(a) Produce a time plot of the data and describe the patterns in the graph. Identify any unusual or unexpected fluctuations in the time series.

(b) Use R function tslm to fit a regression model to the logarithms of these sales data with a linear trend and seasonal component.

(c) Use multiple regression with trend variable and seasonal dummy variables to redo the regression as shown in the lecture example. Check to see that you obtain the same results as tslm.

Answer 1