The accompanying data file contains monthly observations for 5 years

a. Calculate the 12-month centered moving average. (Do not round intermediate calculations. Round your answers to 2 decimal places.) b. Calculate the ratio-to-moving average. (Do not round intermediate calculations. Round your answers to 2 decimal places.) c-1. Calculate the seasonal indices for April and November. (Do not round intermediate calculations. Round your answers to 4 decimal places.) c-2. Interpret the seasonal index for April. (Do not round intermediate calculations. Round your answer to 2 decimal places.) c-3. Interpret the seasonal index for November. (Do not round intermediate calculations. Round your answer to 2 decimal places.)

Year	Month	yt
1	January	13
1	February	17
1	March	15
1	April	12
1	May	32
1	June	15
1	July	21
1	August	17
1	September	33
1	October	15
1	November	34
1	December	21
2	January	26
2	February	10
2	March	14
2	April	19
2	May	17
2	June	14
2	July	27
2	August	30
2	September	25
2	October	15
2	November	18
2	December	27
3	January	24
3	February	11
3	March	19
3	April	23
3	May	19
3	June	18
3	July	31
3	August	18
3	September	15
3	October	31
3	November	34
3	December	27
4	January	23
4	February	22
4	March	17
4	April	24

4	May	17
4	June	24
4	July	15
4	August	19
4	September	33
4	October	19
4	November	16
4	December	39
5	January	17
5	February	19
5	March	25
5	April	30
5	May	18
5	June	17
5	July	19
5	August	36
5	September	19
5	October	26
5	November	21
5	December	35