Finding the Fourth Proportional to 142,139.75, 196,152.80 and 81,722.21

Step by Step Solution

1. Step 1: Write the proportion equation
   142,139.75 : 196,152.80 = 81,722.21 : x
2. Step 2: Convert to fraction form
   142,139.75/196,152.80 = 81,722.21/x
3. Step 3: Cross multiply
   142,139.75x = 196,152.80 × 81,722.21
4. Step 4: Simplify right side
   142,139.75x = 16,030,040,027.61
5. Step 5: Solve for x
   x = 16,030,040,027.61/142,139.75
6. Step 6: Final answer
   x = 112,776.62