Finding the Fourth Proportional to 77,640.56, 107,113.56 and 47,780.72

Step by Step Solution

1. Step 1: Write the proportion equation
   77,640.56 : 107,113.56 = 47,780.72 : x
2. Step 2: Convert to fraction form
   77,640.56/107,113.56 = 47,780.72/x
3. Step 3: Cross multiply
   77,640.56x = 107,113.56 × 47,780.72
4. Step 4: Simplify right side
   77,640.56x = 5,117,963,018.56
5. Step 5: Solve for x
   x = 5,117,963,018.56/77,640.56
6. Step 6: Final answer
   x = 65,918.68