An electrical contractor?s records during the last five weeks indicate the number of the job requests: Week: 1 2 3 4 5 Requests: 20 22 18 21 22 Predict the number of requests for week 6 using each of these methods: a. Naive. b. A four-period moving average. c. Exponential smoothing with alpha=0.30. Use 20 for week2 forecast