Finding the Fourth Proportional to 172,061.85, 258,128.61 and 86,720.67

Step by Step Solution

1. Step 1: Write the proportion equation
   172,061.85 : 258,128.61 = 86,720.67 : x
2. Step 2: Convert to fraction form
   172,061.85/258,128.61 = 86,720.67/x
3. Step 3: Cross multiply
   172,061.85x = 258,128.61 × 86,720.67
4. Step 4: Simplify right side
   172,061.85x = 22,385,086,005.37
5. Step 5: Solve for x
   x = 22,385,086,005.37/172,061.85
6. Step 6: Final answer
   x = 130,099.07