Finding the Fourth Proportional to 128,433.72, 177,245.42 and 71,841.72

Step by Step Solution

1. Step 1: Write the proportion equation
   128,433.72 : 177,245.42 = 71,841.72 : x
2. Step 2: Convert to fraction form
   128,433.72/177,245.42 = 71,841.72/x
3. Step 3: Cross multiply
   128,433.72x = 177,245.42 × 71,841.72
4. Step 4: Simplify right side
   128,433.72x = 12,733,615,834.92
5. Step 5: Solve for x
   x = 12,733,615,834.92/128,433.72
6. Step 6: Final answer
   x = 99,145.43