MasterTech is a new software company that develops and markets productivity software for municipal government applications. Net sales are uniformly distributed between $$600,000$ and $$1,200,000.$ Cost of sales is normally distributed with a mean of $$540,000$ and a standard deviation of $$20,000.$ Selling expenses has a fixed component of that is uniformly distributed between $$75,000$ and $$110,000.$ Administrative expenses are normal with a mean of $$50,000$ and standard deviation of $$3,500.$ Variable expenses are estimated to be $7\%$ of net sales and interest expenses are $$10,000.$ The company is taxed at a $50\%$ rate and the company is interested in a risk profile of net income.

Net income can be found using the following set of equations:

Gross profit $=$ net sales $$ cost of sales

Net operating profit $=$ gross profit $$ administrative expenses $$ selling expenses

Net income before taxes $=$ net operating profit $$ interest expenses

Net income $=$ net income before taxes $$ taxes

Which of the inputs is uncertain and what parameters are associated with those uncertain inputs?