Finding the Fourth Proportional to 39,128.54, 53,997.30 and 21,223.49

Step by Step Solution

1. Step 1: Write the proportion equation
   39,128.54 : 53,997.30 = 21,223.49 : x
2. Step 2: Convert to fraction form
   39,128.54/53,997.30 = 21,223.49/x
3. Step 3: Cross multiply
   39,128.54x = 53,997.30 × 21,223.49
4. Step 4: Simplify right side
   39,128.54x = 1,146,010,886.59
5. Step 5: Solve for x
   x = 1,146,010,886.59/39,128.54
6. Step 6: Final answer
   x = 29,288.37