Finding the Fourth Proportional to 102,919.30, 142,025.59 and 56,980.99

Step by Step Solution

1. Step 1: Write the proportion equation
   102,919.30 : 142,025.59 = 56,980.99 : x
2. Step 2: Convert to fraction form
   102,919.30/142,025.59 = 56,980.99/x
3. Step 3: Cross multiply
   102,919.30x = 142,025.59 × 56,980.99
4. Step 4: Simplify right side
   102,919.30x = 8,092,759,024.91
5. Step 5: Solve for x
   x = 8,092,759,024.91/102,919.30
6. Step 6: Final answer
   x = 78,632.08