Finding the Fourth Proportional to 128,705.67, 177,613.89 and 78,404.67

Step by Step Solution

1. Step 1: Write the proportion equation
   128,705.67 : 177,613.89 = 78,404.67 : x
2. Step 2: Convert to fraction form
   128,705.67/177,613.89 = 78,404.67/x
3. Step 3: Cross multiply
   128,705.67x = 177,613.89 × 78,404.67
4. Step 4: Simplify right side
   128,705.67x = 13,925,758,432.87
5. Step 5: Solve for x
   x = 13,925,758,432.87/128,705.67
6. Step 6: Final answer
   x = 108,198.48