Finding the Fourth Proportional to 259,309.50, 389,029.89 and 72,321

Step by Step Solution

1. Step 1: Write the proportion equation
   259,309.50 : 389,029.89 = 72,321 : x
2. Step 2: Convert to fraction form
   259,309.50/389,029.89 = 72,321/x
3. Step 3: Cross multiply
   259,309.50x = 389,029.89 × 72,321
4. Step 4: Simplify right side
   259,309.50x = 28,135,030,674.69
5. Step 5: Solve for x
   x = 28,135,030,674.69/259,309.50
6. Step 6: Final answer
   x = 108,499.81