Finding the Fourth Proportional to 142,301.80, 196,374.60 and 78,640.72

Step by Step Solution

1. Step 1: Write the proportion equation
   142,301.80 : 196,374.60 = 78,640.72 : x
2. Step 2: Convert to fraction form
   142,301.80/196,374.60 = 78,640.72/x
3. Step 3: Cross multiply
   142,301.80x = 196,374.60 × 78,640.72
4. Step 4: Simplify right side
   142,301.80x = 15,443,039,933.71
5. Step 5: Solve for x
   x = 15,443,039,933.71/142,301.80
6. Step 6: Final answer
   x = 108,523.15