A shop manager has recorded the number of customers over the past few weeks. The results are shown below.
(Data available on the online platform, file CSE27.xlsx.)
a. Graph the data.
b. Find a seven point moving average trend and place it on your graph.
c. Determine the effect of day of week using the additive model (Hint: adapt the approach used for seasonal factors).
d. Calculate the residual factor and construct a graph.
e. Explain any concerns you may have about this model and the improvements you might consider.