Finding the Fourth Proportional to 28,978.68, 39,986.76 and 16,401

Step by Step Solution

1. Step 1: Write the proportion equation
   28,978.68 : 39,986.76 = 16,401 : x
2. Step 2: Convert to fraction form
   28,978.68/39,986.76 = 16,401/x
3. Step 3: Cross multiply
   28,978.68x = 39,986.76 × 16,401
4. Step 4: Simplify right side
   28,978.68x = 655,822,850.76
5. Step 5: Solve for x
   x = 655,822,850.76/28,978.68
6. Step 6: Final answer
   x = 22,631.22