Finding the Fourth Proportional to 28,411.89, 42,625.71 and 12,402.80

Step by Step Solution

1. Step 1: Write the proportion equation
   28,411.89 : 42,625.71 = 12,402.80 : x
2. Step 2: Convert to fraction form
   28,411.89/42,625.71 = 12,402.80/x
3. Step 3: Cross multiply
   28,411.89x = 42,625.71 × 12,402.80
4. Step 4: Simplify right side
   28,411.89x = 528,678,155.99
5. Step 5: Solve for x
   x = 528,678,155.99/28,411.89
6. Step 6: Final answer
   x = 18,607.64