Finding the Fourth Proportional to 99,146.34, 136,839.43 and 56,128.29

Step by Step Solution

1. Step 1: Write the proportion equation
   99,146.34 : 136,839.43 = 56,128.29 : x
2. Step 2: Convert to fraction form
   99,146.34/136,839.43 = 56,128.29/x
3. Step 3: Cross multiply
   99,146.34x = 136,839.43 × 56,128.29
4. Step 4: Simplify right side
   99,146.34x = 7,680,562,451.77
5. Step 5: Solve for x
   x = 7,680,562,451.77/99,146.34
6. Step 6: Final answer
   x = 77,466.93