A company is considering an investment with the following financial information: initial investment is $800,000, project life is 5 years, salvage value is $50,000, unit price is $45/unit, unit variable cost is $18/unit, and fixed annual cost is $320,000. It is estimated that the annual sales volume will be 25,000 units. MARR is 11%. The company is concerned about the impact of sales volume on the project's rate of return. 

a. Please conduct a sensitivity analysis and determine the IRR if the annual sales volume changes by the following percentages from the initial estimate: 

• -60%
• -40%
• -20%
• 0%
• +20%
• +40%
• +60% 

b. Determine the percentage change that causes a reversal in the decision regarding the attractiveness of the project. .