please show how to arrive at answer in Excel and show formula so I can learn, thank you

The two-year interest rate is 10.8% and the expected annual inflation rate is 5.4%. a.What is the expected real interest rate? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.) Expected real interest rate % b-1. If the expected rate of inflation suddenly rises to 7.4%, what does Fisher's theory say about how the real interest rate will change? Real rate does not change Real rate decreases Real rate increases b-2. If the expected rate of inflation suddenly rises to 7.4%, what will be the new nominal rate? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.) Nominal rate %