The following table reports the sale of umbrellas for 16 quarters. Quarter Year 1 Year 2 Year 3 Year 4 1 5 6 10 12 2 2 3 5 9 3 1 1 3 7 4 4 5 8 10 Develop a model using the second quarter as the reference and write down the model's equation accounting for the effect in the data. Round your answers to two decimal places.