Finding the Fourth Proportional to 76,780.47, 105,960.32 and 42,789

Step by Step Solution

1. Step 1: Write the proportion equation
   76,780.47 : 105,960.32 = 42,789 : x
2. Step 2: Convert to fraction form
   76,780.47/105,960.32 = 42,789/x
3. Step 3: Cross multiply
   76,780.47x = 105,960.32 × 42,789
4. Step 4: Simplify right side
   76,780.47x = 4,533,936,132.48
5. Step 5: Solve for x
   x = 4,533,936,132.48/76,780.47
6. Step 6: Final answer
   x = 59,050.64