Moving Average
1. **Problem Statement:** Omar wants to forecast the number of Joseph Smith carvings to be sold in Month 7 using two methods: a 4-month moving average and a 4-month weighted moving average.
2. **Given Data:**
Month: 1, 2, 3, 4, 5, 6
Sales: 40, 58, 45, 54, 48, 44
3. **4-Month Moving Average Formula:**
$$\text{Forecast for Month } n = \frac{\text{Sales}_{n-1} + \text{Sales}_{n-2} + \text{Sales}_{n-3} + \text{Sales}_{n-4}}{4}$$
4. **Calculate 4-Month Moving Average for Month 7:**
Use sales from Months 3, 4, 5, and 6:
$$\frac{45 + 54 + 48 + 44}{4} = \frac{191}{4} = 47.75$$
5. **4-Month Weighted Moving Average Formula:**
$$\text{Forecast for Month } n = w_1 \times \text{Sales}_{n-1} + w_2 \times \text{Sales}_{n-2} + w_3 \times \text{Sales}_{n-3} + w_4 \times \text{Sales}_{n-4}$$
where weights sum to 1.
6. **Given Weights:**
- Last month (Month 6): 0.7
- Two months previous (Month 5): 0.1
- Three months previous (Month 4): 0.1
- Four months previous (Month 3): 0.1
7. **Calculate Weighted Moving Average for Month 7:**
$$0.7 \times 44 + 0.1 \times 48 + 0.1 \times 54 + 0.1 \times 45 = 30.8 + 4.8 + 5.4 + 4.5 = 45.5$$
**Final Answers:**
- 4-month moving average forecast for Month 7: **47.75**
- 4-month weighted moving average forecast for Month 7: **45.50**