Finding the Fourth Proportional to 39,900.42, 55,061.90 and 21,997.09

Step by Step Solution

1. Step 1: Write the proportion equation
   39,900.42 : 55,061.90 = 21,997.09 : x
2. Step 2: Convert to fraction form
   39,900.42/55,061.90 = 21,997.09/x
3. Step 3: Cross multiply
   39,900.42x = 55,061.90 × 21,997.09
4. Step 4: Simplify right side
   39,900.42x = 1,211,201,569.87
5. Step 5: Solve for x
   x = 1,211,201,569.87/39,900.42
6. Step 6: Final answer
   x = 30,355.61