In: Economics
| 
 Period  | 
 Sales ($million)  | 
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| 
 2017 Q1  | 
 2874  | 
||||
| 
 2017 Q2  | 
 3000  | 
||||
| 
 2017 Q3  | 
 2913  | 
||||
| 
 2017 Q4  | 
 2916  | 
||||
| 
 2918 Q1  | 
 2910  | 
||||
| 
 2018 Q2  | 
 3052  | 
||||
| 
 2018 Q3  | 
 3116  | 
||||
| 
 2018 Q4  | 
 3210  | 
||||
| 
 2019 Q1  | 
 3243  | 
||||
| 
 2019 Q2  | 
 3351  | 
||||
| 
 2019 Q3  | 
 3305  | 
||||
| 
 2019 Q4  | 
 3267  | 
The above table represents the quarterly sales (measured in millions of dollars) for the Goodyear Tire from 2017 to 2019.
| Period | Period Number | Sales ($million) | Periods Used | 4 Quarter Moving Average | Value | 4 Quarter Centered Moving Average | Value | Seasonality Index | 
| 2017 Q1 | 1 | 2874 | 0.077347 | |||||
| 1.5 | ||||||||
| 2017 Q2 | 2 | 3000 | 0.080738 | |||||
| 2.5 | 2017 Q1, 2017 Q2, 2017 Q3, 2017 Q4 | =(2874+3000+2913+2916)/4 | 2925.75 | |||||
| 2017 Q3 | 3 | 2913 | =(2925.75+2934.75)/2 | 2930.25 | 0.078397 | |||
| 3.5 | 2017 Q2, 2017 Q3, 2017 Q4, 2018 Q1 | =(3000+2913+2916+2910)/4 | 2934.75 | |||||
| 2017 Q4 | 4 | 2916 | =(2934.75+2947.75)/2 | 2941.25 | 0.078478 | |||
| 4.5 | 2017 Q3, 2017 Q4, 2018 Q1, 2018 Q2 | =(2913+2916+2910+3052)/4 | 2947.75 | |||||
| 2918 Q1 | 5 | 2910 | =(2947.75+2998.5)/2 | 2973.125 | 0.078316 | |||
| 5.5 | 2017 Q4, 2018 Q1, 2018 Q2, 2018 Q3 | =(2916+2910+3052+3116)/4 | 2998.5 | |||||
| 2018 Q2 | 6 | 3052 | =(2998.5+3072)/2 | 3035.25 | 0.082138 | |||
| 6.5 | 2018 Q1, 2018 Q2, 2018 Q3, 2018 Q4 | =(2910+3052+3116+3210)/4 | 3072 | |||||
| 2018 Q3 | 7 | 3116 | =(3072+3155.25)/2 | 3113.625 | 0.08386 | |||
| 7.5 | 2018 Q2, 2018 Q3, 2018 Q4, 2019 Q1 | =(3052+3116+3210+3243)/4 | 3155.25 | |||||
| 2018 Q4 | 8 | 3210 | =(3155.25+3230)/2 | 3192.625 | 0.08639 | |||
| 8.5 | 2018 Q3, 2018 Q4, 2019 Q1, 2019 Q2 | =(3116+3210+3243+3351)/4 | 3230 | |||||
| 2019 Q1 | 9 | 3243 | =(3230+3277.25)/2 | 3253.625 | 0.087278 | |||
| 9.5 | 2018 Q4, 2019 Q1, 2019 Q2, 2019 Q3 | =(3210+3243+3351+3305)/4 | 3277.25 | |||||
| 2019 Q2 | 10 | 3351 | =(3277.25+3291.5)/2 | 3284.375 | 0.090185 | |||
| 10.5 | 2019 Q1, 2019 Q2, 2019 Q3, 2019 Q4 | =(3243+3351+3305+3267)/4 | 3291.5 | |||||
| 2019 Q3 | 11 | 3305 | 0.088947 | |||||
| 11.5 | ||||||||
| 2019 Q4 | 12 | 3267 | 0.087924 | |||||
| TOTAL | 37157 |