• Please use excel and show all work
• Plot these sales against time. What, if any, seasonal pattern do you see in the plot? Explain.
• Deseasonalize the data by calculating the centered moving average. Plot the deseasonalized data on the graph created in (a). Calculate the seasonal index for each quarter. Write a short explanation of why the results make sense.
• Develop a trend for the data USING deseasonalized SALES (NOT ACTUAL SALES) and plot that trend line on the graph developed in (a). Compare the deseasonalized sales data and the trend line. Does there appear to be a cyclical pattern in the data? Explain.

Period	Sales
Mar-01	26.84
Jun-01	26.95
Sep-01	32.21
Dec-01	27.30
Mar-02	26.87
Jun-02	29.82
Sep-02	32.34
Dec-02	29.28
Mar-03	30.07
Jun-03	32.40
Sep-03	35.41
Dec-03	32.15
Mar-04	31.84
Jun-04	35.08
Sep-04	37.80
Dec-04	33.46
Mar-05	33.85
Jun-05	36.73
Sep-05	38.09
Dec-05	32.98
Mar-06	32.93
Jun-06	35.61
Sep-06	39.76
Dec-06	35.32
Mar-07	36.61
Jun-07	39.95
Sep-07	42.69
Dec-07	37.94
Mar-08	38.76
Jun-08	41.57
Sep-08	45.94
Dec-08	42.25
Mar-09	43.75
Jun-09	48.29
Sep-09	54.43
Dec-09	48.11
Mar-10	51.11
Jun-10	53.33
Sep-10	59.71
Dec-10	51.81
Mar-11	52.00
Jun-11	53.71
Sep-11	56.72
Dec-11	49.36
Mar-12	49.30
Jun-12	54.63
Sep-12	55.71
Dec-12	50.43
Mar-13	51.99
Jun-13	56.97
Sep-13	58.61
Dec-13	53.02
Mar-14	57.75
Jun-14	59.87
Sep-14	60.80
Dec-14	56.28
Mar-15	57.67
Jun-15	63.86
Sep-15	66.57
Dec-15	62.44
Mar-16	64.57
Jun-16	71.73
Sep-16	74.31
Dec-16	67.86