In: Statistics and Probability
Consider the following time series data.
| Quarter | Year 1 | Year 2 | Year 3 |
| 1 | 3 | 6 | 7 |
| 2 | 4 | 1 | 8 |
| 3 | 1 | 7 | 5 |
| 4 | 5 | 7 | 8 |
a. Which of the following is a time series plot?
- Select your answer -time series plot #1time series plot #2time series plot #3Item 1
What type of pattern exists in the data?
- Select your answer -upward linear trendnonlinear trend and a seasonal patternlinear trend and a seasonal patternslight curvaturedownward linear trendItem 2
b. Show the four-quarter and centered moving average values for this time series (to 3 decimals if necessary).
| Year | Quarter | Time Series Value | Four-Quarter Moving Average | Centered Moving Average |
| 1 | 1 | 3 | ||
| 2 | 4 | |||
| _________ | ||||
| 3 | 1 | _____ | ||
| __________ | ||||
| 4 | 5 | _________ | ||
| __________ | ||||
| 2 | 1 | 6 | ______ | |
| ________ | ||||
| 2 | 1 | _______ | ||
| ______ | ||||
| 3 | 7 | _______ | ||
| ________ | ||||
| 4 | 7 | ________ | ||
| ________ | ||||
| 3 | 1 | 7 | __________ | |
| ________ | ||||
| 2 | 8 | ________ | ||
| ________ | ||||
| 3 | 5 | |||
| 4 | 8 |
c. Compute seasonal indexes and adjusted seasonal indexes for the four quarters (to 3 decimals).
| Quarter | Seasonal Index |
Adjusted Seasonal Index |
| 1 | ||
| 2 | ||
| 3 | ||
| 4 | ||
| Total |
a) The time seres plot is given by,

The type of pattern exists in the data is seasonal pattern upward linear trend.
| Year | Quater | Time series | 4 point moving total | 4 point oving average | Centered moving average |
| 1 | 1 | 3 | |||
| 2 | 4 | ||||
| 13 | 3.25 | ||||
| 3 | 1 | 3.625 | |||
| 16 | 4 | ||||
| 4 | 5 | 3.625 | |||
| 13 | 3.25 | ||||
| 2 | 1 | 6 | 4 | ||
| 19 | 4.75 | ||||
| 2 | 1 | 5 | |||
| 21 | 5.25 | ||||
| 3 | 7 | 5.375 | |||
| 22 | 5.5 | ||||
| 4 | 7 | 6.375 | |||
| 29 | 7.25 | ||||
| 3 | 1 | 7 | 7 | ||
| 27 | 6.75 | ||||
| 2 | 8 | 6.875 | |||
| 28 | 7 | ||||
| 3 | 5 | ||||
| 4 | 8 |
c) Seasonal indexes and adjusted seasonal indexes for the four quarters.
| Year | Quater | Time series | centered moving average | Seasonal Irregular component |
| 1 | 1 | 3 | ||
| 2 | 4 | |||
| 3 | 1 | 3.625 | 0.276 | |
| 4 | 5 | 3.625 | 1.379 | |
| 2 | 1 | 6 | 4 | 1.500 |
| 2 | 1 | 5 | 0.200 | |
| 3 | 7 | 5.375 | 1.302 | |
| 4 | 7 | 6.375 | 1.098 | |
| 3 | 1 | 7 | 7 | 1.000 |
| 2 | 8 | 6.875 | 1.164 | |
| 3 | 5 | |||
| 4 | 8 |
Seasonal Index :




Total: 1.250 + 0.682+ 0.789+ 1.238 = 3.959
Adjusted Seasonal Index :




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