Finding the Fourth Proportional to 80,335.10, 119,784.43 and 78,128.12

Step by Step Solution

1. Step 1: Write the proportion equation
   80,335.10 : 119,784.43 = 78,128.12 : x
2. Step 2: Convert to fraction form
   80,335.10/119,784.43 = 78,128.12/x
3. Step 3: Cross multiply
   80,335.10x = 119,784.43 × 78,128.12
4. Step 4: Simplify right side
   80,335.10x = 9,358,532,321.17
5. Step 5: Solve for x
   x = 9,358,532,321.17/80,335.10
6. Step 6: Final answer
   x = 116,493.69