The president of a small manufacturing firm is concerned about the continual growth in manufacturing costs in the past several years. The data senes of the cost per unit for the firm's leading product over the past eight years is as follows: Year 1 2 3 Cost/Unit (S) 17.00 21.50 24.50 23.60 Year 5 6 7 8 Cost/Unit ($) 22:20 25.40 26.50 31.00 a. Choose the correct graph for the time series and linear trend. The correct graph is select 4o Cost/Unt. 5 30 25 20 35 10 10 5 Year Time series Linear trend b. Use Excel to develop a simple linear regression model for these data. What average cost increase has the firm been realizing per year? Do not round intermediate calculations. Round your answers to four decimal places. The regression equation is Unit Cost = Year The average cost increase per year is 5 from The president of a small manufacturing firm is concerned about the continual growth in manufacturing costs in the past several years. The data senes of the cost per unit for the firm's leading product over the past eight years is as follows: Year 1 2 3 Cost/Unit (S) 17.00 21.50 24.50 23.60 Year 5 6 7 8 Cost/Unit ($) 22:20 25.40 26.50 31.00 a. Choose the correct graph for the time series and linear trend. The correct graph is select 4o Cost/Unt. 5 30 25 20 35 10 10 5 Year Time series Linear trend b. Use Excel to develop a simple linear regression model for these data. What average cost increase has the firm been realizing per year? Do not round intermediate calculations. Round your answers to four decimal places. The regression equation is Unit Cost = Year The average cost increase per year is 5 from