Finding the Fourth Proportional to 8,403.86, 12,602.79 and 2,780.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,403.86 : 12,602.79 = 2,780.50 : x
2. Step 2: Convert to fraction form
   8,403.86/12,602.79 = 2,780.50/x
3. Step 3: Cross multiply
   8,403.86x = 12,602.79 × 2,780.50
4. Step 4: Simplify right side
   8,403.86x = 35,042,057.60
5. Step 5: Solve for x
   x = 35,042,057.60/8,403.86
6. Step 6: Final answer
   x = 4,169.76