Finding the Fourth Proportional to 99,699.32, 137,423.88 and 86,745.50

Step by Step Solution

1. Step 1: Write the proportion equation
   99,699.32 : 137,423.88 = 86,745.50 : x
2. Step 2: Convert to fraction form
   99,699.32/137,423.88 = 86,745.50/x
3. Step 3: Cross multiply
   99,699.32x = 137,423.88 × 86,745.50
4. Step 4: Simplify right side
   99,699.32x = 11,920,902,495.42
5. Step 5: Solve for x
   x = 11,920,902,495.42/99,699.32
6. Step 6: Final answer
   x = 119,568.55