Finding the Fourth Proportional to 76,801.72, 105,992.55 and 42,821.20

Step by Step Solution

1. Step 1: Write the proportion equation
   76,801.72 : 105,992.55 = 42,821.20 : x
2. Step 2: Convert to fraction form
   76,801.72/105,992.55 = 42,821.20/x
3. Step 3: Cross multiply
   76,801.72x = 105,992.55 × 42,821.20
4. Step 4: Simplify right side
   76,801.72x = 4,538,728,182.06
5. Step 5: Solve for x
   x = 4,538,728,182.06/76,801.72
6. Step 6: Final answer
   x = 59,096.70