****I need answer (c)*****

Consider the following time series data: Week 1 2 3 4 6. Value 18 13 16 11 17 14 a. Construct a time series plot. What type of pattern exists in the data? b. Develop a three-week moving average for this time series. Compute MSE and a forecast for Week 7. c. Use a = 0.2 to compute the exponential smoothing values for the time series. Compute MSE and a forecast for Week 7. d. Compare the three-week moving average forecast with the exponential smoothing forecast using a = 0.2. Which appears to provide the better forecast based on MSE? Explain. e. Use trial and error to find a value of the exponential smoothing coefficient a that results in a smaller MSE than what you calculated for a = 0.2