Finding the Fourth Proportional to 142,112.10, 212,758.55 and 86,816.10

Step by Step Solution

1. Step 1: Write the proportion equation
   142,112.10 : 212,758.55 = 86,816.10 : x
2. Step 2: Convert to fraction form
   142,112.10/212,758.55 = 86,816.10/x
3. Step 3: Cross multiply
   142,112.10x = 212,758.55 × 86,816.10
4. Step 4: Simplify right side
   142,112.10x = 18,470,867,552.66
5. Step 5: Solve for x
   x = 18,470,867,552.66/142,112.10
6. Step 6: Final answer
   x = 129,973.93