Finding the Fourth Proportional to 39,901.89, 55,064.59 and 21,997.20

Step by Step Solution

1. Step 1: Write the proportion equation
   39,901.89 : 55,064.59 = 21,997.20 : x
2. Step 2: Convert to fraction form
   39,901.89/55,064.59 = 21,997.20/x
3. Step 3: Cross multiply
   39,901.89x = 55,064.59 × 21,997.20
4. Step 4: Simplify right side
   39,901.89x = 1,211,266,468.83
5. Step 5: Solve for x
   x = 1,211,266,468.83/39,901.89
6. Step 6: Final answer
   x = 30,356.12