Finding the Fourth Proportional to 78,787.61, 108,728.42 and 42,978.93

Step by Step Solution

1. Step 1: Write the proportion equation
   78,787.61 : 108,728.42 = 42,978.93 : x
2. Step 2: Convert to fraction form
   78,787.61/108,728.42 = 42,978.93/x
3. Step 3: Cross multiply
   78,787.61x = 108,728.42 × 42,978.93
4. Step 4: Simplify right side
   78,787.61x = 4,673,030,937.30
5. Step 5: Solve for x
   x = 4,673,030,937.30/78,787.61
6. Step 6: Final answer
   x = 59,311.75