Finding the Fourth Proportional to 51,339.30, 71,978.70 and 51,339.30

Step by Step Solution

1. Step 1: Write the proportion equation
   51,339.30 : 71,978.70 = 51,339.30 : x
2. Step 2: Convert to fraction form
   51,339.30/71,978.70 = 51,339.30/x
3. Step 3: Cross multiply
   51,339.30x = 71,978.70 × 51,339.30
4. Step 4: Simplify right side
   51,339.30x = 3,695,336,072.91
5. Step 5: Solve for x
   x = 3,695,336,072.91/51,339.30
6. Step 6: Final answer
   x = 71,978.70