A coin sold at auction in 2019 for $9,179,000. The coin had a face value of $20 when it was issued in 1793 and had been previously sold for $220,000 in 1970.

a. At what annual rate did the coin appreciate from its first minting to the 1970 sale? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)

b. What annual rate did the 1970 buyer earn on his purchase? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)

c. At what annual rate did the coin appreciate from its first minting to the 2019 sale? (Do not round