I need help with case study 6.1 on pages 307 to 308 on Optimizing a Timber Harvest in the book spreadsheet modeling and decision analysis edition 7. There is a partial solution on chegg but I'm not getting the correct answer and feel that I'm missing part of a couple equations, specifically for the flow column, Build road column?, link column, net flow column and harvest colums. Please refer to the question on chegg for specifics. I got a terrible and incomplete answer last time I asked.I'm looking for formulas only.Thank youOptimizing a Timber HarvestThis is case 6.1 from the book Spreadsheet Modeling and Decision AnalysisThis problem is about a large area of forest in Virginia, where volume of wood has increase by 81%. This area is about 15.4 million acres, 77% which is owned privately. There are many factors that need to be considered when determining which trees should be harvested.Figure 6.36 in the book shows a tract of forested land that has been sectioned off into 12 harvestable areas. Area 2 has the only access to the forest with a paved road, so timber cut must be transported through area 2. There are no roads through the forest currently, so new roads will need to be paved. The routes that are allowed are based on geography of the land and some other factors. They are also shown in figure 6.36.Not all areas of the forest have to be harvested. However, to harvest any area a road will need to built to that area. The cost of building each section of road (in $1000s) is in the following figure. The net value of harvestable timber in each area is as follows:Harvested Value (in 1000s)Area123456789101112Value$15$7$10$12$8$17$14$18$13$12$10$11Create a spreadsheet modelWhat is the optimal solutions?Suppose the cost of building the road connecting area 4 and 5 dropped to $12,000. What impact does this have on the optimal solution?