Finding the Fourth Proportional to 61,128.72, 91,511.28 and 54,714.06

Step by Step Solution

1. Step 1: Write the proportion equation
   61,128.72 : 91,511.28 = 54,714.06 : x
2. Step 2: Convert to fraction form
   61,128.72/91,511.28 = 54,714.06/x
3. Step 3: Cross multiply
   61,128.72x = 91,511.28 × 54,714.06
4. Step 4: Simplify right side
   61,128.72x = 5,006,953,664.60
5. Step 5: Solve for x
   x = 5,006,953,664.60/61,128.72
6. Step 6: Final answer
   x = 81,908.37