Finding the Fourth Proportional to 39,128.17, 53,996.90 and 21,223.17

Step by Step Solution

1. Step 1: Write the proportion equation
   39,128.17 : 53,996.90 = 21,223.17 : x
2. Step 2: Convert to fraction form
   39,128.17/53,996.90 = 21,223.17/x
3. Step 3: Cross multiply
   39,128.17x = 53,996.90 × 21,223.17
4. Step 4: Simplify right side
   39,128.17x = 1,145,985,388.17
5. Step 5: Solve for x
   x = 1,145,985,388.17/39,128.17
6. Step 6: Final answer
   x = 29,287.99