4. During potatoes harvesting season, Farmer Brown picks potatoes at a rate of 1,000 kg/day and ediately puts them into his barn. The picking process costs $2/ kg. The potatoes stay in the barn for 20 day,on average. 15% of the potatoes are sold as premiumpotatoesfor $7/kg. 80% are sold as regular potatoes for $2/kg. The remaining 5% are spoiled and are removed from the barn at a cost of $1/kg. a) Draw a stock and flow diagram to determine the potatoes, revenues and expenses at time t. Add arrows, stocks, flows, variables, etc. as appropriate. For each stock and flow, indicate the units and the equation. If you use, exogenous variables indicate their value and units. b) Farmer Brown's annual profit is $45,000 and he deposits it into a High Interest Savings Account which pays interest of 7% annually with continuous compounding. Using numeric / Euler integration determine the value in the account at time t-2 years using dt-0.5 and an initial balance of $10,000. Pieminwn arn 4. During potatoes harvesting season, Farmer Brown picks potatoes at a rate of 1,000 kg/day and ediately puts them into his barn. The picking process costs $2/ kg. The potatoes stay in the barn for 20 day,on average. 15% of the potatoes are sold as premiumpotatoesfor $7/kg. 80% are sold as regular potatoes for $2/kg. The remaining 5% are spoiled and are removed from the barn at a cost of $1/kg. a) Draw a stock and flow diagram to determine the potatoes, revenues and expenses at time t. Add arrows, stocks, flows, variables, etc. as appropriate. For each stock and flow, indicate the units and the equation. If you use, exogenous variables indicate their value and units. b) Farmer Brown's annual profit is $45,000 and he deposits it into a High Interest Savings Account which pays interest of 7% annually with continuous compounding. Using numeric / Euler integration determine the value in the account at time t-2 years using dt-0.5 and an initial balance of $10,000. Pieminwn arn